diff --git a/.DS_Store b/.DS_Store
index c3e5a9a..ecbfb07 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/README.md b/README.md
index e69de29..b229569 100644
--- a/README.md
+++ b/README.md
@@ -0,0 +1,82 @@
+# Calculator
+
+เว็บแอปพลิเคชันเพื่อแสดงตัวอย่างการเขียนกรณีทดสอบ โดยใช้ `Laravel 5.4` และ `PHPUnit` เพื่อการทดสอบ
+
+## ความต้องการเบื้องต้น
+| รายการซอฟต์แวร์ | รุ่นขั้นต่ำ | รุ่นที่แนะนำ | รุ่นที่ใช้พัฒนา |
+|---------------|:------:|:--------:|:---------:|            
+| PHP           | >=5.7  | 5.7      | 7         |
+| composer      | 1.4.2  | 1.4.2    | 1.4.2     |
+| phpunit       | 5.7    | 5.7      | 6.2.2     |
+
+## ขั้นตอนการทดสอบ
+
+1. ดาวน์โหลด `we-inc/calculator` ด้วยคำสั่ง
+    ```bash
+    git clone https://github.com/we-inc/calculator
+    ```
+
+1. อัพเดต lib ด้วยคำสั่ง `composer`
+    ```bash
+    cd calculator && \
+        composer update
+    ```
+    
+1. กรณีทดสอบจะอยู่อยู่ภายในโฟลเดอร์
+    ```
+    + tests
+        + Features
+        |  + AddControllerTest.php
+        |  + MinusControllerTest.php
+        + Unit
+    ```
+
+1. สร้างกรณีทดสอบโดยใช้คำสั่งด้านล่าง โดยคำสั่งนี้จะสร้างคลาสซึ่งเป็น Unit Test ชื่อ `SomeTestCaseTest` (โดยที่กรณีทดสอบนั้นต้องลงท้ายชื่อด้วย `Test`)
+    ```bash
+    php artisan make:test SomeTestCaseTest
+    ```
+    เพื่อสร้างกรณีทดสอบสำหรับหน้าที่การใช้งานตัวไป และ
+
+    ```bash
+    php artisan make:test SomeControllerTest --unit
+    ```
+    สำหรับกรณีทดสอบสำหรับคลาสใดคลาสหนึ่ง
+    
+1. ภายในคลาส `SomeTestCaseTest` ที่สร้างขึ้นมานั้น จะมีซอร์สโค้ดดังตัวอย่างด้านล่าง
+    ```php
+    <?php
+
+        namespace Tests\Feature;
+        
+        use Tests\TestCase;
+        use Illuminate\Foundation\Testing\WithoutMiddleware;
+        use Illuminate\Foundation\Testing\DatabaseMigrations;
+        use Illuminate\Foundation\Testing\DatabaseTransactions;
+        
+        class SomeTestCaseTest extends TestCase
+        {
+            /**
+             * A basic test example.
+             *
+             * @return void
+             */
+            public function testExample()
+            {
+                $this->assertTrue(true);
+            }
+        }
+    ```
+    ด้านในจะปรากฏเมธอด `testExample()` ซึ่งเมธอดที่มีชื่อขึ้นต้นด้วย `test` นั้นจะบรรจุกรณีทดสอบ ซึ่งจะนำมาใช้ทดสอบคุณสมบัติต่าง ๆ ของซอฟต์แวร์ตามที่ต้องการ
+
+1. ทดสอบซอฟต์แวร์ด้วยกรณีทดสอบที่สร้างขึ้นด้วยคำสั่ง `phpunit` ณ โฟลเดอร์ชั้นบนสุดของโปรเจค
+    ```php
+    phpunit
+    ```
+
+    เมื่อผลการทดสอบเสร็จสิ้น จะมีผลลัพธ์การดำเนินการแสดงให้ทราบ
+
+## ข้อมูลเพิ่มเติม
+
+ข้อมูลเพิ่มเติมสำหรับกรณีทดสอบ 
+- [Laravel: Getting Started](https://laravel.com/docs/master/testing)
+- [Illuminate: TestCase API](https://laravel.com/api/master/Illuminate/Foundation/Testing/TestCase.html)
diff --git a/app/.DS_Store b/app/.DS_Store
index eea122a..d770ce8 100644
Binary files a/app/.DS_Store and b/app/.DS_Store differ
diff --git a/app/Http/.DS_Store b/app/Http/.DS_Store
index fc608b1..7aa839d 100644
Binary files a/app/Http/.DS_Store and b/app/Http/.DS_Store differ
diff --git a/app/Http/Controllers/AddController.php b/app/Http/Controllers/AddController.php
deleted file mode 100644
index 098e1e7..0000000
--- a/app/Http/Controllers/AddController.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Controllers;
-
-use App\Http\Controllers\Controller;
-use Illuminate\Support\Facades\Input;
-
-class AddController extends Controller{
-
-	public function calculate($ans = null){
-		if (strpos($ans, '_') !== false) {
-    		$new = (float)str_replace('_','.',$ans);
-		}
-		else 
-			$new = $ans;
-
-
-		if(Input::has('num1') && Input::has('num2'))
-			$new = Input::get('num1') + Input::get('num2');
-		elseif(Input::has('num1'))
-			$new = Input::get('num1');
-
-		$route = str_replace(".","_",strval($new));
-
-		return view('add', array('ans' => $new, 'route' => $route));
-	}
-
-}
diff --git a/app/Http/Controllers/DivideController.php b/app/Http/Controllers/DivideController.php
deleted file mode 100644
index 75ee54d..0000000
--- a/app/Http/Controllers/DivideController.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Controllers;
-
-use App\Http\Controllers\Controller;
-use Illuminate\Support\Facades\Input;
-
-class DivideController extends Controller{
-
-		public function calculate($ans = null){
-		if (strpos($ans, '_') !== false) {
-    		$new = (float)str_replace('_','.',$ans);
-		}
-		else 
-			$new = $ans;
-
-
-		if(Input::has('num1') && Input::has('num2'))
-			$new = Input::get('num1') / Input::get('num2');
-		elseif(Input::has('num1'))
-			$new = Input::get('num1');
-
-		$route = str_replace(".","_",strval($new));
-
-		return view('divide', array('ans' => $new, 'route' => $route));
-	}
-
-}
\ No newline at end of file
diff --git a/app/Http/Controllers/InputController.php b/app/Http/Controllers/InputController.php
new file mode 100644
index 0000000..dddf9a1
--- /dev/null
+++ b/app/Http/Controllers/InputController.php
@@ -0,0 +1,89 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Http\Controllers\Controller;
+use Illuminate\Support\Facades\Input;
+
+use App\Module\Add;
+use App\Module\Minus;
+use App\Module\Multiply;
+use App\Module\Divide;
+
+class InputController extends Controller{
+
+    public function add(){
+
+    	$add = new Add();
+
+        $answer = null;
+        if(Input::has('num1') && Input::has('num2')){
+            if(is_numeric(Input::get('num1')) && is_numeric(Input::get('num2'))){
+                $answer = $add->calculate(Input::get('num1'),Input::get('num2'));
+            }
+            else{
+                $answer = "Numbers are required";
+            }
+        }
+
+        return view('add', array('answer' => $answer));
+    }
+
+    public function minus(){
+
+    	$minus = new Minus();
+
+        $answer = null;
+        if(Input::has('num1') && Input::has('num2')){
+            if(is_numeric(Input::get('num1')) && is_numeric(Input::get('num2'))){
+                $answer = $minus->calculate(Input::get('num1'),Input::get('num2'));
+            }
+            else{
+                $answer = "Numbers are required";
+            }
+        }
+
+        return view('minus', array('answer' => $answer));
+    }
+
+    public function multiply(){
+
+    	$multiply = new Multiply();
+
+        $answer = null;
+        if(Input::has('num1') && Input::has('num2')){
+            if(is_numeric(Input::get('num1')) && is_numeric(Input::get('num2'))){
+                $answer = $multiply->calculate(Input::get('num1'),Input::get('num2'));
+            }
+            else{
+                $answer = "Numbers are required";
+            }
+        }
+
+        return view('multiply', array('answer' => $answer));
+    }
+
+    public function divide(){
+
+    	$divide = new Divide();
+
+        $answer = null;
+        if(Input::has('num1') && Input::has('num2')){
+            if(is_numeric(Input::get('num1')) && is_numeric(Input::get('num2'))){
+                if(Input::get('num2') != 0)
+                    $answer = $divide->calculate(Input::get('num1'),Input::get('num2'));
+                else
+                    $answer = "Cannot divided by zero";
+            }
+            else{
+                $answer = "Numbers are required";
+            }
+        }
+
+        return view('divide', array('answer' => $answer));
+    }
+
+}
+
+
+?>
\ No newline at end of file
diff --git a/app/Http/Controllers/MinusController.php b/app/Http/Controllers/MinusController.php
deleted file mode 100644
index e4e93de..0000000
--- a/app/Http/Controllers/MinusController.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Controllers;
-
-use App\Http\Controllers\Controller;
-use Illuminate\Support\Facades\Input;
-
-class MinusController extends Controller{
-
-		public function calculate($ans = null){
-		if (strpos($ans, '_') !== false) {
-    		$new = (float)str_replace('_','.',$ans);
-		}
-		else 
-			$new = $ans;
-
-
-		if(Input::has('num1') && Input::has('num2'))
-			$new = Input::get('num1') - Input::get('num2');
-		elseif(Input::has('num1'))
-			$new = Input::get('num1');
-
-		$route = str_replace(".","_",strval($new));
-
-		return view('minus', array('ans' => $new, 'route' => $route));
-	}
-
-}
\ No newline at end of file
diff --git a/app/Http/Controllers/MultiplyController.php b/app/Http/Controllers/MultiplyController.php
deleted file mode 100644
index 29928ff..0000000
--- a/app/Http/Controllers/MultiplyController.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Controllers;
-
-use App\Http\Controllers\Controller;
-use Illuminate\Support\Facades\Input;
-
-class MultiplyController extends Controller{
-
-		public function calculate($ans = null){
-		if (strpos($ans, '_') !== false) {
-    		$new = (float)str_replace('_','.',$ans);
-		}
-		else 
-			$new = $ans;
-
-
-		if(Input::has('num1') && Input::has('num2'))
-			$new = Input::get('num1') * Input::get('num2');
-		elseif(Input::has('num1'))
-			$new = Input::get('num1');
-
-		$route = str_replace(".","_",strval($new));
-
-		return view('multiply', array('ans' => $new, 'route' => $route));
-	}
-
-}
\ No newline at end of file
diff --git a/app/Module/Add.php b/app/Module/Add.php
new file mode 100644
index 0000000..14eaaff
--- /dev/null
+++ b/app/Module/Add.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Module;
+
+class Add
+{
+
+	public function calculate($num1,$num2){
+		return $num1 + $num2;
+	}
+}
+
+?>
\ No newline at end of file
diff --git a/app/Module/Divide.php b/app/Module/Divide.php
new file mode 100644
index 0000000..37acc61
--- /dev/null
+++ b/app/Module/Divide.php
@@ -0,0 +1,12 @@
+<?php 
+
+namespace App\Module;
+	
+class Divide
+{	
+	public function calculate($num1,$num2){
+		return $num1 / $num2;
+	}
+}
+
+?>
\ No newline at end of file
diff --git a/app/Module/Minus.php b/app/Module/Minus.php
new file mode 100644
index 0000000..8cd2b55
--- /dev/null
+++ b/app/Module/Minus.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Module;
+
+class Minus
+{
+
+	public function calculate($num1,$num2){
+		return $num1 - $num2;
+	}
+}
+
+?>
\ No newline at end of file
diff --git a/app/Module/Multiply.php b/app/Module/Multiply.php
new file mode 100644
index 0000000..97bcc11
--- /dev/null
+++ b/app/Module/Multiply.php
@@ -0,0 +1,12 @@
+<?php 
+
+namespace App\Module;
+
+class Multiply
+{
+	public function calculate($num1,$num2){
+		return $num1 * $num2;
+	}
+}
+
+?>
\ No newline at end of file
diff --git a/composer.lock b/composer.lock
index 91e43c9..09fac84 100644
--- a/composer.lock
+++ b/composer.lock
@@ -237,16 +237,16 @@
         },
         {
             "name": "laravel/framework",
-            "version": "v5.4.31",
+            "version": "v5.4.32",
             "source": {
                 "type": "git",
                 "url": "https://github.com/laravel/framework.git",
-                "reference": "fc1afa6b981cadbe3be8be65b49ca82e3eb9b9c9"
+                "reference": "b8300578d159199b1195413b67318c79068cd24d"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/laravel/framework/zipball/fc1afa6b981cadbe3be8be65b49ca82e3eb9b9c9",
-                "reference": "fc1afa6b981cadbe3be8be65b49ca82e3eb9b9c9",
+                "url": "https://api.github.com/repos/laravel/framework/zipball/b8300578d159199b1195413b67318c79068cd24d",
+                "reference": "b8300578d159199b1195413b67318c79068cd24d",
                 "shasum": ""
             },
             "require": {
@@ -362,7 +362,7 @@
                 "framework",
                 "laravel"
             ],
-            "time": "2017-08-02T15:24:31+00:00"
+            "time": "2017-08-03T12:59:42+00:00"
         },
         {
             "name": "laravel/tinker",
@@ -483,16 +483,16 @@
         },
         {
             "name": "league/flysystem",
-            "version": "1.0.40",
+            "version": "1.0.41",
             "source": {
                 "type": "git",
                 "url": "https://github.com/thephpleague/flysystem.git",
-                "reference": "3828f0b24e2c1918bb362d57a53205d6dc8fde61"
+                "reference": "f400aa98912c561ba625ea4065031b7a41e5a155"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/thephpleague/flysystem/zipball/3828f0b24e2c1918bb362d57a53205d6dc8fde61",
-                "reference": "3828f0b24e2c1918bb362d57a53205d6dc8fde61",
+                "url": "https://api.github.com/repos/thephpleague/flysystem/zipball/f400aa98912c561ba625ea4065031b7a41e5a155",
+                "reference": "f400aa98912c561ba625ea4065031b7a41e5a155",
                 "shasum": ""
             },
             "require": {
@@ -513,13 +513,13 @@
                 "league/flysystem-aws-s3-v3": "Allows you to use S3 storage with AWS SDK v3",
                 "league/flysystem-azure": "Allows you to use Windows Azure Blob storage",
                 "league/flysystem-cached-adapter": "Flysystem adapter decorator for metadata caching",
-                "league/flysystem-copy": "Allows you to use Copy.com storage",
                 "league/flysystem-eventable-filesystem": "Allows you to use EventableFilesystem",
                 "league/flysystem-rackspace": "Allows you to use Rackspace Cloud Files",
                 "league/flysystem-sftp": "Allows you to use SFTP server storage via phpseclib",
                 "league/flysystem-webdav": "Allows you to use WebDAV storage",
                 "league/flysystem-ziparchive": "Allows you to use ZipArchive adapter",
-                "spatie/flysystem-dropbox": "Allows you to use Dropbox storage"
+                "spatie/flysystem-dropbox": "Allows you to use Dropbox storage",
+                "srmklive/flysystem-dropbox-v2": "Allows you to use Dropbox storage for PHP 5 applications"
             },
             "type": "library",
             "extra": {
@@ -562,7 +562,7 @@
                 "sftp",
                 "storage"
             ],
-            "time": "2017-04-28T10:15:08+00:00"
+            "time": "2017-08-06T17:41:04+00:00"
         },
         {
             "name": "monolog/monolog",
@@ -960,16 +960,16 @@
         },
         {
             "name": "ramsey/uuid",
-            "version": "3.6.1",
+            "version": "3.7.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/ramsey/uuid.git",
-                "reference": "4ae32dd9ab8860a4bbd750ad269cba7f06f7934e"
+                "reference": "0ef23d1b10cf1bc576e9d865a7e9c47982c5715e"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/ramsey/uuid/zipball/4ae32dd9ab8860a4bbd750ad269cba7f06f7934e",
-                "reference": "4ae32dd9ab8860a4bbd750ad269cba7f06f7934e",
+                "url": "https://api.github.com/repos/ramsey/uuid/zipball/0ef23d1b10cf1bc576e9d865a7e9c47982c5715e",
+                "reference": "0ef23d1b10cf1bc576e9d865a7e9c47982c5715e",
                 "shasum": ""
             },
             "require": {
@@ -1038,7 +1038,7 @@
                 "identifier",
                 "uuid"
             ],
-            "time": "2017-03-26T20:37:53+00:00"
+            "time": "2017-08-04T13:39:04+00:00"
         },
         {
             "name": "swiftmailer/swiftmailer",
@@ -2251,22 +2251,22 @@
         },
         {
             "name": "phpdocumentor/reflection-docblock",
-            "version": "3.2.0",
+            "version": "3.2.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpDocumentor/ReflectionDocBlock.git",
-                "reference": "46f7e8bb075036c92695b15a1ddb6971c751e585"
+                "reference": "183824db76118b9dddffc7e522b91fa175f75119"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/46f7e8bb075036c92695b15a1ddb6971c751e585",
-                "reference": "46f7e8bb075036c92695b15a1ddb6971c751e585",
+                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/183824db76118b9dddffc7e522b91fa175f75119",
+                "reference": "183824db76118b9dddffc7e522b91fa175f75119",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.5",
                 "phpdocumentor/reflection-common": "^1.0@dev",
-                "phpdocumentor/type-resolver": "^0.4.0",
+                "phpdocumentor/type-resolver": "^0.3.0",
                 "webmozart/assert": "^1.0"
             },
             "require-dev": {
@@ -2292,20 +2292,20 @@
                 }
             ],
             "description": "With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.",
-            "time": "2017-07-15T11:38:20+00:00"
+            "time": "2017-08-04T20:55:59+00:00"
         },
         {
             "name": "phpdocumentor/type-resolver",
-            "version": "0.4.0",
+            "version": "0.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpDocumentor/TypeResolver.git",
-                "reference": "9c977708995954784726e25d0cd1dddf4e65b0f7"
+                "reference": "fb3933512008d8162b3cdf9e18dba9309b7c3773"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpDocumentor/TypeResolver/zipball/9c977708995954784726e25d0cd1dddf4e65b0f7",
-                "reference": "9c977708995954784726e25d0cd1dddf4e65b0f7",
+                "url": "https://api.github.com/repos/phpDocumentor/TypeResolver/zipball/fb3933512008d8162b3cdf9e18dba9309b7c3773",
+                "reference": "fb3933512008d8162b3cdf9e18dba9309b7c3773",
                 "shasum": ""
             },
             "require": {
@@ -2339,7 +2339,7 @@
                     "email": "me@mikevanriel.com"
                 }
             ],
-            "time": "2017-07-14T14:27:02+00:00"
+            "time": "2017-06-03T08:32:36+00:00"
         },
         {
             "name": "phpspec/prophecy",
diff --git a/public/asset/equal-symbol.png b/public/asset/equal-symbol.png
new file mode 100644
index 0000000..47125af
Binary files /dev/null and b/public/asset/equal-symbol.png differ
diff --git a/resources/views/add.blade.php b/resources/views/add.blade.php
index a08cb7d..cd3a1eb 100644
--- a/resources/views/add.blade.php
+++ b/resources/views/add.blade.php
@@ -75,14 +75,10 @@
                 <div class="title m-b-md">
                     Add (บวก)
                 </div>
-                {{ Form::open(array('action'=> 'AddController@calculate','method'=> 'POST')) }}
+                {{ Form::open(array('action'=> 'InputController@add','method'=> 'POST')) }}
                 <div class="grid-x grid-margin-x">
                     <div class="medium-4 cell">
-                    @if ($ans !== null)
-                        <input type="number" name="num1" value="{{ $ans }}" readonly>
-                    @else 
                         <input type="number" name="num1" step="any">
-                    @endif
                     </div>
                     <div class="medium-2 cell">
                         <h4>+</h4>
@@ -91,27 +87,20 @@
                         <input type="number" name="num2" step="any">
                     </div>
                     <div class="medium-2 cell">
-                        <button type="submit" class="hollow button button expanded">=</button>
+                        <button type="submit" class="button primary expanded"><img src="/asset/equal-symbol.png" /></button>
                     </div>
                 </div>
-                <input type="hidden" name="ans" value="{{$ans}}">
                 {{ Form::close() }}
                 <hr>
                 <div class="grid-x grid-margin-x">
-                    <div class="medium-3 cell">
-                        <a class="hollow button large expanded" href="{{ route('add',['ans' => $route]) }}">+</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('minus',['ans' => $route]) }}">-</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('multiply',['ans' => $route]) }}">x</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('divide',['ans' => $route]) }}">/</a>
+                    <div class="medium-12">
+                        <center><h3>{{ $answer }}</h3></center>
                     </div>
                 </div>
-               
+                <hr>
+                <div class="links">
+                    <a class="clear button secondary" href="{{ route('home') }}"> Back (กลับสู่หน้าหลัก)</a>
+                </div>
             </div>
         </div>
                 
diff --git a/resources/views/divide.blade.php b/resources/views/divide.blade.php
index 4168f66..ee6f69e 100644
--- a/resources/views/divide.blade.php
+++ b/resources/views/divide.blade.php
@@ -75,14 +75,10 @@
                 <div class="title m-b-md">
                     Divide (หาร)
                 </div>
-                {{ Form::open(array('action'=> 'DivideController@calculate','method'=> 'POST')) }}
+                {{ Form::open(array('action'=> 'InputController@divide','method'=> 'POST')) }}
                 <div class="grid-x grid-margin-x">
                     <div class="medium-4 cell">
-                    @if ($ans !== null)
-                        <input type="number" name="num1" value="{{ $ans }}" readonly>
-                    @else 
                         <input type="number" name="num1" step="any">
-                    @endif
                     </div>
                     <div class="medium-2 cell">
                         <h4>/</h4>
@@ -91,27 +87,20 @@
                         <input type="number" name="num2" step="any">
                     </div>
                     <div class="medium-2 cell">
-                        <button type="submit" class="hollow button button expanded" href="#">=</button>
+                        <button type="submit" class="button primary expanded"><img src="/asset/equal-symbol.png" /></button>
                     </div>
                 </div>
-                <input type="hidden" name="ans" value="{{$ans}}">
                 {{ Form::close() }}
                 <hr>
                 <div class="grid-x grid-margin-x">
-                    <div class="medium-3 cell">
-                        <a class="hollow button large expanded" href="{{ route('add',['ans' => $route]) }}">+</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('minus',['ans' => $route]) }}">-</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('multiply',['ans' => $route]) }}">x</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('divide',['ans' => $route]) }}">/</a>
+                    <div class="medium-12">
+                        <center><h3>{{ $answer }}</h3></center>
                     </div>
                 </div>
-               
+                <hr>
+                <div class="links">
+                    <a class="clear button secondary" href="{{ route('home') }}"> Back (กลับสู่หน้าหลัก)</a>
+                </div>
             </div>
         </div>
                 
diff --git a/resources/views/minus.blade.php b/resources/views/minus.blade.php
index ca56703..7f93edf 100644
--- a/resources/views/minus.blade.php
+++ b/resources/views/minus.blade.php
@@ -75,14 +75,10 @@
                 <div class="title m-b-md">
                     Minus (ลบ)
                 </div>
-                {{ Form::open(array('action'=> 'MinusController@calculate','method'=> 'POST')) }}
+                {{ Form::open(array('action'=> 'InputController@minus','method'=> 'POST')) }}
                 <div class="grid-x grid-margin-x">
                     <div class="medium-4 cell">
-                    @if ($ans !== null)
-                        <input type="number" name="num1" value="{{ $ans }}" readonly>
-                    @else 
                         <input type="number" name="num1" step="any">
-                    @endif
                     </div>
                     <div class="medium-2 cell">
                         <h4>-</h4>
@@ -91,27 +87,20 @@
                         <input type="number" name="num2" step="any">
                     </div>
                     <div class="medium-2 cell">
-                        <button type="submit" class="hollow button button expanded">=</button>
+                        <button type="submit" class="button primary expanded"><img src="/asset/equal-symbol.png" /></button>
                     </div>
                 </div>
-                <hr>
-                <input type="hidden" name="ans" value="{{$ans}}">
                 {{ Form::close() }}
+                <hr>
                 <div class="grid-x grid-margin-x">
-                    <div class="medium-3 cell">
-                        <a class="hollow button large expanded" href="{{ route('add',['ans' => $route]) }}">+</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('minus',['ans' => $route]) }}">-</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('multiply',['ans' => $route]) }}">x</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('divide',['ans' => $route]) }}">/</a>
+                    <div class="medium-12">
+                        <center><h3>{{ $answer }}</h3></center>
                     </div>
                 </div>
-               
+                <hr>
+                <div class="links">
+                    <a class="clear button secondary" href="{{ route('home') }}"> Back (กลับสู่หน้าหลัก)</a>
+                </div>
             </div>
         </div>
                 
diff --git a/resources/views/multiply.blade.php b/resources/views/multiply.blade.php
index 202b06d..ce6dfab 100644
--- a/resources/views/multiply.blade.php
+++ b/resources/views/multiply.blade.php
@@ -75,14 +75,10 @@
                 <div class="title m-b-md">
                     Multiply (คูณ)
                 </div>
-                {{ Form::open(array('action'=> 'MultiplyController@calculate','method'=> 'POST')) }}
+                {{ Form::open(array('action'=> 'InputController@multiply','method'=> 'POST')) }}
                 <div class="grid-x grid-margin-x">
                     <div class="medium-4 cell">
-                    @if ($ans !== null)
-                        <input type="number" name="num1" value="{{ $ans }}" readonly>
-                    @else 
                         <input type="number" name="num1" step="any">
-                    @endif
                     </div>
                     <div class="medium-2 cell">
                         <h4>x</h4>
@@ -91,27 +87,20 @@
                         <input type="number" name="num2" step="any">
                     </div>
                     <div class="medium-2 cell">
-                        <button type="submit" class="hollow button button expanded" href="#">=</button>
+                        <button type="submit" class="button primary expanded"><img src="/asset/equal-symbol.png" /></button>
                     </div>
                 </div>
-                <input type="hidden" name="ans" value="{{$ans}}">
                 {{ Form::close() }}
                 <hr>
                 <div class="grid-x grid-margin-x">
-                    <div class="medium-3 cell">
-                        <a class="hollow button large expanded" href="{{ route('add',['ans' => $route]) }}">+</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('minus',['ans' => $route]) }}">-</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('multiply',['ans' => $route]) }}">x</a>
-                    </div>
-                    <div class="medium-3 cell">
-                        <a class="hollow button button large expanded" href="{{ route('divide',['ans' => $route]) }}">/</a>
+                    <div class="medium-12">
+                        <center><h3>{{ $answer }}</h3></center>
                     </div>
                 </div>
-               
+                <hr>
+                <div class="links">
+                    <a class="clear button secondary" href="{{ route('home') }}"> Back (กลับสู่หน้าหลัก)</a>
+                </div>
             </div>
         </div>
                 
diff --git a/resources/views/welcome.blade.php b/resources/views/welcome.blade.php
index 369d0f1..eadda77 100644
--- a/resources/views/welcome.blade.php
+++ b/resources/views/welcome.blade.php
@@ -83,12 +83,10 @@
                 </div>
 
                 <div class="links">
-                    <a href="https://laravel.com/docs">Documentation</a>
-                    <a href="https://laracasts.com">Laracasts</a>
-                    <a href="https://laravel-news.com">News</a>
-                    <a href="https://forge.laravel.com">Forge</a>
-                    <a href="https://github.com/laravel/laravel">GitHub</a>
-                    <a href="{{ route('add') }}">Add</a>
+                    <a class="clear button" href="{{ route('add') }}">+ Add (บวก)</a>
+                    <a class="clear button" href="{{ route('minus') }}">- Minus (ลบ)</a>
+                    <a class="clear button" href="{{ route('multiply') }}">x Multiply (คูณ)</a>
+                    <a class="clear button" href="{{ route('divide') }}">/ Divide (หาร)</a>
                 </div>
             </div>
         </div>
diff --git a/routes/web.php b/routes/web.php
index 9824d8f..ce6902f 100644
--- a/routes/web.php
+++ b/routes/web.php
@@ -13,12 +13,12 @@
 
 Route::get('/', function () {
     return view('welcome');
-});
+})->name('home');
 
-Route::match(['get','post'],'add/{ans?}','AddController@calculate')->name('add');
+Route::match(['get','post'],'add','InputController@add')->name('add');
 
-Route::match(['get','post'],'minus/{ans?}','MinusController@calculate')->name('minus');
+Route::match(['get','post'],'minus','InputController@minus')->name('minus');
 
-Route::match(['get','post'],'multiply/{ans?}','MultiplyController@calculate')->name('multiply');
+Route::match(['get','post'],'multiply','InputController@multiply')->name('multiply');
 
-Route::match(['get','post'],'divide/{ans?}','DivideController@calculate')->name('divide');
\ No newline at end of file
+Route::match(['get','post'],'divide','InputController@divide')->name('divide');
\ No newline at end of file
diff --git a/tests/Feature/AddControllerTest.php b/tests/Feature/AddControllerTest.php
new file mode 100644
index 0000000..dcf0912
--- /dev/null
+++ b/tests/Feature/AddControllerTest.php
@@ -0,0 +1,92 @@
+<?php
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class AddControllerTest extends TestCase
+{
+    
+    public function testAddMainViewDisplay()
+    {
+        $response = $this->get('/add');
+        
+        $response->assertStatus(200)
+            ->assertSee('Add (บวก)')
+            ;
+    }
+
+    public function testAnswerShouldDisplay()
+    {
+        $response = $this->post('/add', ['num1' => 1, 'num2' => 2]);
+
+        $response->assertStatus(200)
+            ->assertSee('3')
+            ;
+    }
+
+    public function testAnswerShouldReceiveFormAnotherView() 
+    {
+        $response = $this->post('/add', ['num1' => 5, 'num2' => 0]);
+
+        $response->assertStatus(200)
+            ->assertSee('5')
+            ;
+    }
+
+    public function testCharacterShouldDisplayWarningMessage() 
+    {
+        $response = $this->post('/add', ['num1' => 4, 'num2' => 'a']);
+
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+
+        $response = $this->post('/add', ['num1' => 'a', 'num2' => 'b']);
+
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+    }
+
+    public function testFloatShouldBeAdded() 
+    {
+        $response = $this->post('/add', ['num1' => 3.2, 'num2' => 1.8]);
+
+        $response->assertStatus(200)
+            ->assertSee('5')
+        ;
+        
+        $response = $this->post('/add', ['num1' => 3, 'num2' => 1.0]);
+        $response->assertStatus(200)
+            ->assertSee('4')
+        ;
+        
+        $response = $this->post('/add', ['num1' => 3.0, 'num2' => 1]);
+        $response->assertStatus(200)
+            ->assertSee('4')
+        ;
+        
+        $response = $this->post('/add', ['num1' => 0.0, 'num2' => 0.0]);
+        $response->assertStatus(200)
+            ->assertSee('0')
+        ;
+    }
+
+    public function testNegativeShouldBeAdd() 
+    {
+        $response = $this->post('/add', ['num1' => 1, 'num2' => -1]);
+        $response->assertStatus(200)
+                ->assertSee('0')
+        ;
+        
+        $response = $this->post('/add', ['num1' => 1, 'num2' => -1]);
+        $response->assertStatus(200)
+                ->assertSee('0')
+        ;
+    }
+    
+}
diff --git a/tests/Feature/DivideControllerTest.php b/tests/Feature/DivideControllerTest.php
new file mode 100644
index 0000000..b10da5e
--- /dev/null
+++ b/tests/Feature/DivideControllerTest.php
@@ -0,0 +1,97 @@
+<?php
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class DivideControllerTest extends TestCase
+{
+    public function testAddMainViewDisplay()
+    {
+        $response = $this->get('/divide');
+        
+        $response->assertStatus(200)
+            ->assertSee('Divide (หาร)')
+            ;
+    }
+
+    public function testAnswerShouldDisplay()
+    {
+        $response = $this->post('/divide', ['num1' => 1, 'num2' => 2]);
+
+        $response->assertStatus(200)
+            ->assertSee('0.5')
+            ;
+    }
+
+    public function testAnswerShouldReceiveFormAnotherView() 
+    {
+        $response = $this->post('/divide', ['num1' => 5, 'num2' => 5]);
+
+        $response->assertStatus(200)
+            ->assertSee('1')
+            ;
+    }
+
+    public function testCharacterShouldDisplayWarningMessage() 
+    {
+        $response = $this->post('/divide', ['num1' => 4, 'num2' => 'a']);
+
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+
+        $response = $this->post('/divide', ['num1' => 'a', 'num2' => 'b']);
+
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+    }
+
+    public function testFloatShouldBeDivided() 
+    {
+        $response = $this->post('/divide', ['num1' => 3, 'num2' => 1.5]);
+
+        $response->assertStatus(200)
+            ->assertSee('2')
+        ;
+        
+        $response = $this->post('/divide', ['num1' => 1, 'num2' => 0.5]);
+        $response->assertStatus(200)
+            ->assertSee('2')
+        ;
+        
+        $response = $this->post('/divide', ['num1' => 3.0, 'num2' => 2]);
+        $response->assertStatus(200)
+            ->assertSee('1.5')
+        ;
+        
+        $response = $this->post('/divide', ['num1' => 10, 'num2' => 2.5]);
+        $response->assertStatus(200)
+            ->assertSee('4')
+        ;
+    }
+
+    public function testNegativeShouldBeDivided() 
+    {
+        $response = $this->post('/divide', ['num1' => -1, 'num2' => -1]);
+        $response->assertStatus(200)
+                ->assertSee('1')
+        ;
+        
+        $response = $this->post('/divide', ['num1' => 2, 'num2' => -4]);
+        $response->assertStatus(200)
+                ->assertSee('-0.5')
+        ;
+    }
+
+    public function testZeroShouldNotBeDivider(){
+    	$response = $this->post('/divide', ['num1' => 40, 'num2' => 0]);
+        $response->assertStatus(200)
+                ->assertSee('Cannot divided by zero')
+        ;
+    }
+}
diff --git a/tests/Feature/MinusControllerTest.php b/tests/Feature/MinusControllerTest.php
new file mode 100644
index 0000000..e9aa978
--- /dev/null
+++ b/tests/Feature/MinusControllerTest.php
@@ -0,0 +1,99 @@
+<?php
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class MinusControllerTest extends TestCase
+{
+
+    public function testMinusMainViewDisplay()
+    {
+        $response = $this->get('/minus');
+        
+        $response->assertStatus(200)
+            ->assertSee('Minus (ลบ)')
+            ;
+            
+    }
+
+    public function testMinusAnswerShouldDisplay()
+    {
+        $response = $this->post('/minus', ['num1' => 1, 'num2' => 1]);
+
+        $response->assertStatus(200)
+            ->assertSee('0')
+            ;
+    }
+
+    public function testAnswerShouldReceiveFormAnotherView() 
+    {
+        $response = $this->post('/minus', ['num1' => 0, 'num2' => 0]);
+
+        $response->assertStatus(200)
+            ->assertSee('0')
+            ;
+    }
+
+    public function testCharacterShouldDisplayWarningMessage() 
+    {
+        $response = $this->post('/minus', ['num1' => 1, 'num2' => 'a']);
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+
+        $response = $this->post('/minus', ['num1' => 'a', 'num2' => 1]);
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+
+        $response = $this->post('/minus', ['num1' => 'a', 'num2' => 'b']);
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+    }
+
+    public function testFloatShouldBeMinus() 
+    {
+        $response = $this->post('/minus', ['num1' => 3.2, 'num2' => 1.2]);
+        $response->assertStatus(200)
+            ->assertSee('2')
+        ;
+        
+        $response = $this->post('/minus', ['num1' => 3, 'num2' => 1.0]);
+        $response->assertStatus(200)
+            ->assertSee('2')
+        ;
+        
+        $response = $this->post('/minus', ['num1' => 3.0, 'num2' => 1]);
+        $response->assertStatus(200)
+            ->assertSee('2')
+        ;
+        
+        $response = $this->post('/minus', ['num1' => 0.0, 'num2' => 0.0]);
+        $response->assertStatus(200)
+            ->assertSee('0')
+        ;
+    }
+
+    public function testNegativeShouldBeMinus() 
+    {
+        $response = $this->post('/minus', ['num1' => 1, 'num2' => -1]);
+        $response->assertStatus(200)
+                ->assertSee('2')
+        ;
+        
+        $response = $this->post('/minus', ['num1' => -1, 'num2' => -1]);
+        $response->assertStatus(200)
+                ->assertSee('0')
+        ;
+        
+        $response = $this->post('/minus', ['num1' => -1, 'num2' => 2]);
+        $response->assertStatus(200)
+                ->assertSee('-3')
+        ;
+    }
+}
diff --git a/tests/Feature/MultiplyControllerTest.php b/tests/Feature/MultiplyControllerTest.php
new file mode 100644
index 0000000..a953d0a
--- /dev/null
+++ b/tests/Feature/MultiplyControllerTest.php
@@ -0,0 +1,90 @@
+<?php
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class MultiplyControllerTest extends TestCase
+{
+    public function testAddMainViewDisplay()
+    {
+        $response = $this->get('/multiply');
+        
+        $response->assertStatus(200)
+            ->assertSee('Multiply (คูณ)')
+            ;
+    }
+
+    public function testAnswerShouldDisplay()
+    {
+        $response = $this->post('/multiply', ['num1' => 1, 'num2' => 2]);
+
+        $response->assertStatus(200)
+            ->assertSee('2')
+            ;
+    }
+
+    public function testAnswerShouldReceiveFormAnotherView() 
+    {
+        $response = $this->post('/multiply', ['num1' => 5, 'num2' => 0]);
+
+        $response->assertStatus(200)
+            ->assertSee('0')
+            ;
+    }
+
+    public function testCharacterShouldDisplayWarningMessage() 
+    {
+        $response = $this->post('/multiply', ['num1' => 4, 'num2' => 'a']);
+
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+
+        $response = $this->post('/multiply', ['num1' => 'a', 'num2' => 'b']);
+
+        $response->assertStatus(200)
+            ->assertSee('Numbers are required')
+            ;
+    }
+
+    public function testFloatShouldBeMultiplied() 
+    {
+        $response = $this->post('/multiply', ['num1' => 2.0, 'num2' => 2.2]);
+
+        $response->assertStatus(200)
+            ->assertSee('4.4')
+        ;
+        
+        $response = $this->post('/multiply', ['num1' => 3, 'num2' => 1.0]);
+        $response->assertStatus(200)
+            ->assertSee('3')
+        ;
+        
+        $response = $this->post('/multiply', ['num1' => 3.0, 'num2' => 2]);
+        $response->assertStatus(200)
+            ->assertSee('6')
+        ;
+        
+        $response = $this->post('/multiply', ['num1' => 1.5, 'num2' => 10]);
+        $response->assertStatus(200)
+            ->assertSee('15')
+        ;
+    }
+
+    public function testNegativeShouldBeMultiplied() 
+    {
+        $response = $this->post('/multiply', ['num1' => -1, 'num2' => -1]);
+        $response->assertStatus(200)
+                ->assertSee('1')
+        ;
+        
+        $response = $this->post('/multiply', ['num1' => 2, 'num2' => -4]);
+        $response->assertStatus(200)
+                ->assertSee('-8')
+        ;
+    }
+}
diff --git a/tests/Feature/SomeTestCaseTest.php b/tests/Feature/SomeTestCaseTest.php
new file mode 100644
index 0000000..2eb34f1
--- /dev/null
+++ b/tests/Feature/SomeTestCaseTest.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class SomeTestCaseTest extends TestCase
+{
+    /**
+     * A basic test example.
+     *
+     * @return void
+     */
+    public function testExample()
+    {
+        $this->assertTrue(true);
+    }
+}
diff --git a/tests/Unit/SomeControllerTest.php b/tests/Unit/SomeControllerTest.php
new file mode 100644
index 0000000..29d3af4
--- /dev/null
+++ b/tests/Unit/SomeControllerTest.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Tests\Unit;
+
+use Tests\TestCase;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class SomeControllerTest extends TestCase
+{
+    /**
+     * A basic test example.
+     *
+     * @return void
+     */
+    public function testExample()
+    {
+        $this->assertTrue(true);
+    }
+}