Boxes with Names

Variables and assignment

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• A variable is a named box; “x = …” puts a value in it.
• The right side is worked out first, using current values.
• Assigning copies a value; overwriting destroys the old one.

Steps

1. Variables
2. A copy, not a link
3. Swapping two boxes
4. Work backwards
5. Squaring again and again
6. A swap without a spare box