DOS Calculator

This is how we can use the Windows command prompt as Calculator

C:\>set /a 2+2
4
C:\>set /a 2*(9/2)
8
C:\>set /a (2*9)/2
9
C:\>set /a "31>>2"
7

Note that we had to quote the shift operator since it would otherwise be misinterpreted as a "redirect stdout and append" operator.