teaching machines

The Law of Doubled Digit Transposition Over Multiplication

My son is learning long division at school. He was intimidated by it, so we started practicing for just a few minutes every day after school. The format is simple: I generate two numbers, a big dividend and a small divisor, and he divides them. One day I wanted the quotient to be 99 because […]

Five through Fifteen

On our walks home from school, my 8-year-old son has been telling me of a math problem that he has not been able to solve. Yesterday, after a week of not finding a solution, he wrote down the problem on paper for us to investigate together. Here is the task in my own words: Distribute […]