Lesson 2 — Binary Search: The Power of Halving

Level: Master — roughly Grade 9 / ages 14–15 Duration: 25–35 minutes Format: A halving-search game in the browser Concept: On sorted data, halving each time makes the step count grow very slowly (logarithmically) instead of with the data size

Learning Objective

Kids apply the halving strategy within a guess budget and explain why the data must be sorted first.

Do It Together (Parent-Child Co-participation)

Play 1–1000 with a parent, taking turns holding the secret number — whoever guesses the middle every time always wins.