@echo off
title Calculator
:start
cls
echo This is  a simple calculator.
echo Type in add for addition, sub for subtraction.
echo mul for multiplication or div for division.
set /p answer=
if %answer% equ add goto add
if %answer% equ sub goto sub
if %answer% equ mul goto mul
if %answer% equ div goto div
if %answer% neq add goto start
:add
cls
set result=ERROR
echo Please type in the first number to add.
set /p num1=
echo Please type in the second number.
set /p num2=
set /a result=num1+num2
echo = %result%
pause
goto start
:sub
cls
set result=ERROR
echo Please type in the first number to subtract.
set /p num1=
echo Please type in the second number.
set /p num2=
set /a result=num1-num2
echo = %result%
pause
goto start
:mul
cls
set result=ERROR
echo Please type in the first number to multiply.
set /p num1=
echo Please type in the second number.
set /p num2=
set /a result=num1*num2
echo = %result%
pause
goto start
:div
cls
set result=ERROR
echo Please type in the first number to divide.
set /p num1=
echo Please type in the second number.
set /p num2=
set /a result=num1/num2
echo = %result%
pause
goto start