the command processor CMD.EXE comes with a mini-calculator that can perform simple arithmetic on 32-bit signed integers:
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
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
