Code:
from random import * 

def main():
  showInformation("Welcome to the Math Tutor!")
  n= randrange(1,1000)
  m= randrange(1,1000)
  useranswer= requestInteger("Answer this addition problem\n " + str(n) + "\n" "+ " +str (m))
  sum= (m+n)

if useranswer == sum: # error here
  showInformation ("correct!")
else:
  showInformation (str(useranswer)
...