Lesson 3 — Swap the Boxes (A Classic Puzzle)

Age: Grades 4–6 (ages 9–12) Duration: 20 minutes Format: Web game (play right away, no prep needed) Concept: Variables — swapping values needs a "temporary box" — a puzzle every programmer must pass

Learning Objective

Kids understand the classic "swap two variables" puzzle — why you need a temporary box, and can order the swap steps correctly.

Do It Together (Parent-Child Co-participation)

Try it for real: 2 glasses of colored water + 1 empty glass. Swap the colors without mixing — fun and crystal clear.