Fix some minor typos

Author: pH-7

README.md

@@ -1,9 +1,9 @@
 # Simple Java Calculator
 
-Originally this project was written using Eclipse, but I have migrated it to NetBeans.
-This calculator is simple with an easy code to help novices learn how to operate a calculator.
+This project was originally written using Eclipse, but I have migrated it to NetBeans.
+This calculator is simple with an easy code to help novices learn how to create a calculator program with Java.
 
-If you use the executable file "calculator.jar" and that it does not run, you can type "java -jar /your_calculator_directory/calculator.jar" in your terminal.
+If you use the executable "SimpleJavaCalculator.jar" file and that doesn't work, you can type `java -jar /your_calculator_directory/SimpleJavaCalculator.jar` in your terminal.
 
 
 ![Example: Java Calculator](Screenshots/screenshot.png)