In the play, Isa teaches math to elementary school students using an abacus.

We stumbled upon a great article today about how contemporary schools are using the age-old abacus as a way to teach mental math. Here’s an excerpt below. Find the whole article, “I learned how to do math with the ancient abacus — and it changed my life” by Ulrich Boser HERE on Vox.

A few years ago, I stood in a small basement classroom just outside of New York City, watching a high schooler named Serena Stevenson answer math questions in rapid succession.

An instructor read out numbers —

74,470

70,809

98,402

— and Stevenson added them in her head. For each question, she closed her eyes, and then the fingers of her right hand began to twitch, a progression of plucks and jerks. The movements were fast and exact.

For almost an hour, she used the abacus-based approach to solve math problems. Sometimes she would get problems wrong and smile and shrug. But she also answered many of the problems correctly, including the addition of multiple five-digit numbers in her head.

The key to her success was an ancient technology called the abacus. As I discovered while reporting on a book on the science of learning, the typical abacus has small discs that move up and down on thin posts. The small discs have different values, and the four beads on the bottom have a value of 1. The discs at the top have a value of 5. To calculate a problem, you move the discs up and down until you get to a solution.