100’s Trick

Last week, I sat in a meeting where an adult suggested teaching a student the “100s trick” to solve 100 × 100. My response was an emphatic no. Not because efficiency does not matter, but because my hope for the student was something  bigger than getting one correct answer. I wanted the student to understand what 100 × 100 actually means. Too often, students are handed shortcuts before they build meaning. 

When students understand multiplication conceptually, they begin to see relationships and patterns. They can think about 100 groups of 100, picture a 100 by 100 square, and understand why the product is 10,000. From there, their thinking can naturally scale to ideas like 1,000 × 1,000 and beyond. Students may even begin to notice patterns on their own, like how multiplying by powers of ten changes numbers and place value. That kind of understanding is powerful because it transfers to new situations and helps students reason through problems they have never seen before.

This is a big shift in mathematics education today. The goal is not simply to help students get answers quickly. The goal is to help students make sense of numbers, notice structure, explain their thinking, and develop lasting number sense. A trick may help a student answer one problem, but understanding helps students build mathematical confidence that grows over time. As a teacher, I am far more interested in helping students make sense of mathematics than memorize disconnected rules. 

I am curious to know if teachers in other countries feel the same way.