Ответ:

import random

def GenEx(count):

   signs = ['+', '-', '*', '/']

   for _ in range(count):

       fn = random.randint(-20, 20)

       sn = random.randint(-20, 20)

       ex = '{0} {1} {2}'.format(fn, random.choice(signs), sn)

       yield (ex + ' = ?', eval(ex))

IsGameRun = True

while IsGameRun:

   TrueAnsws = 0

   for ex, check in GenEx(2):

       print(ex)

       resvAnsw = float(input())

       if resvAnsw == check: TrueAnsws += 1;

   IsRetry = input('You correctly solved '+str(TrueAnsws)+' examples. Do you want to try again? Y/N \n')

   if IsRetry == 'Y': IsGameRun = True

   else: IsGameRun = False

Объяснение: