Equal arm balance

Contents Overview


An equal arm balance is one of the most important tools for learners to experience for a better understanding of algebra.

A researcher gave a list of mathematical experiences to groups of students in algebra classes. Students who checked, experience with an equal arm balance, was by far the experience with the highest correlation to high algebra achievement. Followed by and related to understand and use a variable in multiple roles and understand the equal sign.

Toy balance

Equal arm balance toy


Equal arm balance (Commercially available)

Equal arm balance numbers to 10

Learners can explore equal arm balances by distributing different weights or masses on each side to discover different combinations that balance.

Equal arm balance with weights

Balance with weights at 2 and 4

Balance close up with weights at 2 and 4

Mathematical relationship

In the example above 4 weights at the 2 spot on the left side will balance 1 weight at the 8 spot on the right side.

Learners who discover relationships that balance and generalize a concrete and formal relationship will do better with the study of algebra and equations.



Equal arm balance with K'Nex®


Equal arm balance 1


Center support


Equal arm balance 1


Balance top view

Equal arm balance 1


Equal arm balance

KNex equal arm balance 2



Dr. Robert Sweetland's notes
[Home: homeofbob.com & thehob.net ]