I used this script as a 3 part lesson on Python for a 4th grade class.

multiplication_battle.py

import time
import random

#Introduction
print "Hello, Players!"
print "Welcome to Multiplication Battles!"
print ""

#Input information
player1 = raw_input("What is your name, Player 1? ")
player1_points = 0
player2 = raw_input("What is your name, Player 2? ")
player2_points = 0 
length_per_round = int(raw_input("How many seconds do you want each round to be? "))
highest_num = int(raw_input("What's the largest number you want to multiply? "))

#Launch Player1's game
print ""
raw_input("{}! Hit any key to start your time.".format(player1))
current_time = time.time()
end_time = current_time + length_per_round
while current_time <= end_time:
  
  #Do math
  a = random.randint(0, highest_num)
  b = random.randint(0, highest_num)
  c = a*b
  answer = int(raw_input("What is {}x{}? ".format(a,b)))
  
  #Check if right or wrong
  if answer == c:
    print "You're Correct!"
    player1_points += 1
  else:
    print "Sorry. {}x{}={}.".format(a,b,c)
  
  #Must update the time at the end of each loop.
  current_time = time.time()

print "You scored {} points!".format(player1_points)

#Get ready for Player2
print ""
raw_input("{}! Hit any key to start your time.".format(player2))
current_time = time.time()
end_time = current_time + length_per_round
while current_time <= end_time:
  
  #Do math
  a = random.randint(0, highest_num)
  b = random.randint(0, highest_num)
  c = a*b
  
  #Check if right or wrong
  answer = int(raw_input("What is {}x{}? ".format(a,b)))
  if answer == c:
    print "You're Correct!"
    player2_points += 1
  else:
    print "Sorry. {}x{}={}.".format(a,b,c)
    
  #Must update the time at the end of each loop.
  current_time = time.time()
print "You scored {} points!".format(player2_points)

#Decide a winner
print ""
if player1_points > player2_points:
  print "{} wins! Good job!".format(player1)
elif player2_points > player1_points:
  print "{} wins! Good job!".format(player2)
else:
  print "It was a tie! You two should play again!"