Asking students to solve problems mentally, without paper and pencil, is always revealing and often surprising. I thought that asking students to solve 100 ÷ 3 would be sort of a slam dunk. My, was I wrong!

Good Questions for Math Teaching is a Math Solutions book that has long been one of my favorites. It’s a resource that I dip into when I feel the need for something fresh. And it speaks directly to our current shelter-in-place coronavirus crisis as many of us look for ways to mathematically engage students online, children at home, or both. Here are samples to get you started. I’ll continue to post more ideas on Twitter (@mburnsmath).

I’m often surprised by what I learn when I interview students. Watch this 46-second video clip of Jonah solving 100 ÷ 3. Then read how I used the clip in a lesson with a class of fifth graders, and also read the letters the students wrote to Jonah.

Last year, I agreed to meet with a friend’s sixth-grade son. Oscar’s math teacher had raised an alarm for my friend and her husband about Oscar’s math progress. They were shocked. Oscar did his homework and was proficient with paper-and-pencil math. What was the problem?