Mathematicians love a good puzzle. Even something as abstract as multiplying matrices (two-dimensional tables of numbers) can feel like a game when you try to find the most efficient way to do it.

Egan J Chernoff received and receives funding from SSHRC (Social Sciences and Humanities Research Council of Canada) which is not explicitly related to this article. Rina Zazkis received funding from ...

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their ...