About Book Finder Bot
Book Finder Bot teaches binary search, one of the most important ideas in computer science, as a library game. The books on the shelf are in number order but their numbers are hidden. Open a book and the robot tells you whether the one you want comes before or after it, so one try can rule out half the shelf.
Always opening the middle of what is left is the halving trick: 7 books need at most 3 tries, 15 books 4, 31 books 5, 63 books 6 and 127 books only 7. Guess-my-number rounds use the same idea, finding any number from 1 to 100 in 7 guesses and from 1 to 1000 in 10. Early lessons grey out the books you have ruled out; later you keep track yourself.
Finding every book within the try limit earns three stars, so children discover that guessing or searching one by one is far slower. The game explains that doubling the shelf adds only one more try, which is why a computer can search a million names in about 20 steps. Stars build robot helpers for the library.
Best for ages 7+
Free to play. No ads, no sign-up, nothing to download. Privacy
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