Fourth graders solve the problem 5 ÷ 4 in the context of sharing cookies, figuring out how to share five cookies equally with four people. The students came up with six different solutions―all of them correct! (Try and think of what they might be before continuing to read.)

Have you ever asked students to solve 12.6 x 10, and they respond that the answer is 12.60? I have, many times. Students who do this apply a pattern that works when they multiply whole numbers by 10—they tack on a zero to the end of the number they’re multiplying. But then they apply the same pattern when working with decimals. What can we do?

I believe strongly that mistakes are learning opportunities. At least that’s what I regularly tell students. But it sometimes feels different when the mistakes are mine . . . and especially when they are pedagogical mistakes that I make while teaching. That happened to me recently when teaching a lesson to fourth graders.

Lessons using beans and scoops have long been part of my teaching repertoire. I’ve used beans, scoops, and jars to engage students in all grade levels with a variety of mathematical ideas. In this post, I write about how I recently taught a lesson to give students experience with estimation, averages, multiplication, and more. Read about how I planned the lesson, how it unfolded, and suggestions for extensions and other lessons.

Have you ever thought about this numerical sequence—0, 1, 2, 3, 4, 5, 7, 8, 10, 12? What does the sequence have to do with unicycles, bicycles, and tricycles? And what's my mathematical and pedagogical quandary? Read more and find out.

Read how 7th graders collected and analyzed data about the frequency of letters. They chose sentences, recorded the frequency of letters, and put their data on a class chart. Then we compared the class results to the actual frequencies of letters. Engaging the students in collecting their own data gave them an authentic math experience, not rigged by me in any way.

My grandson Jeffrey just turned 11 and I created a book to celebrate his birthday. Now I’m thinking that making books like this might be a good class project for students. Take a look.

A long-standing instructional practice has been to teach students how to multiply (or add, subtract, or divide) and then, after the students have learned to compute, give them word problems to solve. In this post I present a lesson with a different approach, where word problems become the lead and reason for learning to compute.

Students’ ideas often amaze me, and Lydia’s is one of the most suprising examples. She used 7 x 3 = 21 to figure out that 8 x 4 = 32. She reasoned that since the factors in 7 x 3 were each 1 less than the factors in 8 x 4, she’d just increase each digit in the answer, changing 21 to 32. She was correct! Read about Lydia's discovery, what I did, and what I learned.

After I told Steven, the man seated next to me on an airplane, that I was a math teacher, he described the Dealing in Horses problem that he was given at a corporate management training session. The problem has been one of my teaching staples ever since.

My friend Ann sent me an email about her unsettling experience at the supermarket deli counter. Ann has never felt particularly confident with her math ability, and I was pleased (and amused) that she asserted herself in this situation. Also, Ann’s comment to me about the work we face as math teachers rang true.