@echo off
setlocal enableDelayedExpansion
set /a A=%random%%%5*9+1
set /a B=(%random%%%3+1)*3
set fuhao="+-*/
:calc
set/a n+=1
set/a RS=%A%!fuhao:~%n%,1!%B%
echo %A% !fuhao:~%n%,1! %B% = %RS%
if not "!fuhao:~%n%,1!"=="/" goto calc
pause>nul
@echo off
setlocal enableDelayedExpansion
set /a A=%random%%%5*9
set /a B=(%random%%%3+1)*3
set fuhao=+-*/a
pause>nul
set /a n=0
:calc
set /a RS=%A% !fuhao:~%n%,1! %B%
echo !A! !fuhao:~%n%,1! !B! = %RS%
set /a n+=1
if not "!fuhao:~%n%,1!"=="a" goto :calc
pause>nul
goto :eof