Balance Scales

What does “=” really mean?

An interactive lesson with 9 steps, about 8 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• An equation is like a level scale: both sides have the same value.
• Doing the same thing to both sides keeps it balanced.
• To solve, use balanced moves until $x$ is alone on one side.

Steps

1. A mystery box
2. Take the same off both sides
3. Breaking the balance
4. An equation is a balance
5. Balanced moves
6. Two boxes
7. Split both sides
8. Boxes on both sides
9. No scale this time