Image of the Week: Estimating Length

Estimating Length

One of our most popular Off You Go activities invites students to hunt for objects that are about 10 cm long to build an understanding of this linear measurement. These kinds of activities build deep embodied understandings of units of measure that students can then use to estimate lengths in the future, just as number benchmarks help students estimate quantity. For students to really know how to use units of measure, they need a deeply held sense of each unit and how it relates to their world and, in the case of lengths like 6 inches, their bodies. When someone says, “6 inches” we want students to feel their hands moving apart just that distance, knowing how 6 inches relates to the size of their hands, arms, and torso. To develop this understanding, they need lots of opportunities to physically interact with objects and their measurements. So, share this image with students and then send them off to find object that they feel are about 6 inches long.

Some students might resist the idea that we can hold mathematical ideas in our bodies, but this is at the heart of learning and doing mathematics. From an early age, we count on fingers, we manipulate figures and puzzle pieces, we navigate three-dimensional space physically, and we embody concepts like symmetry. When looking for objects that weigh measure about 6 inches, encourage students to only start with their eyes and then quickly move to their hands to feel what that distance is like compared to their bodies.

And if you want to explore other lengths, don’t fret! We have Off You Go activities to look for objects that measure about 1 inch, 3 inches, 1 foot, 1 centimeter, and 10 centimeters.

To multiplicity, cheers!

Jen Munson and the multiplicity lab group