Sine of the Times Blog

A Follow-Up to the Interior Angle Sum

This post is a follow-up to Sarah Stephens’ guest post of a week ago, in which she described a lesson using embodied cognition to help students make sense of the interior angle sum theorem for triangles, not just as an abstract concept, but as a property grounded in their concrete physical experiences. The day before...

The Interior Angle Sum: An Embodied Investigation

[This guest post by Sarah Stephens, a senior at Pennsylvania State University, describes a lesson she created as part of her Senior Honors Thesis on leveraging embodied cognition to help students develop abstract mathematical concepts.] As a soon-to-be classroom mathematics teacher, I have taken special interest in the field of embodied cognition and integrating it...

Race to the Burning Tent

How can you identify a lover of math? Casually mention a burning tent and notice if her first thought is how to minimize her path to a river and then to the tent to douse the flames. Here is a full statement of this classic geometry problem: Ah, the great outdoors. Camping, the fresh air,...

Pirate Treasure Awaits

In a 2018 blog post, I presented George Gamow’s pirate treasure problem, which can neatly be solved by capitalizing on the geometry of complex numbers. There’s more treasure to be had, however, so get ready for another adventure! An island contains a giant boulder, a lighthouse, a cave, and a jail. Among a pirate’s belongings,...

Tanton’s Two-Pan Balance Puzzle

I’m a big fan of pan-balance puzzles in which you’re given a two-pan balance and asked to use it to uncover a counterfeit coin or determine the weight of a coin. One classic example is the following puzzle: You have 12 coins that all look exactly the same. One is counterfeit and is either heavier...

Splitting Arrays

In last month’s Construct a Building post, I presented any array model in which students construct the rooms and floors of a building as a way of representing multiplication. Now I’d like to follow up with a similar array model that allows students to take a problem they don’t know, like 8 × 7, and break...