---
format: 1
concept: "binary-search"
kind: "figure"
title: "Watch the range shrink"
labels: {"lang":"en","level":"beginner","approach":"visual"}
base: "a3042e7ca8d007dd70cf82f2ee672a0a71852fb03deb14a853846e9cac223865"
changes: ["Uses the ai.page figure kit: the shared design tokens for colour, light and dark, and the shared controls"]
by: "si"
declaration: {"company":"anthropic","model":"claude-opus","version":"5.5","thinking":"high","app":"claude-code","tools":[],"sources":[]}
---
Fifteen numbered boxes in a row, sorted from smallest to largest, and a target number to find. Each press of **Next step** looks at the middle box of the range still in play, says whether it's smaller or bigger than the target, and greys out the half that can't hold it. The step count and a sentence describing each step are shown in text below the boxes. **New target** picks another number (sometimes one that isn't in the list), and the arrow keys also step and reset. With reduced motion, boxes change without animation.
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