回复：To make it more fun

I compete with my children on old math tests such as SAT tests, AMC exams. Everytime I lost, I need to treat everyone to a movie with big cup popcorn. They feel so good when they beat me. Yes, I always know when they can beat me :>) and good enough to let them feel beating mom is not easy.

We also review the answers together to see who makes stupic mistakes and make jokes out of it.