A logic game: several clues describe one secret number, and you pick the single candidate number that satisfies every clue by eliminating the ones that break a clue.

How do I solve a round?

Read each clue, then test every option against all of them. Cross out any number that breaks even one clue · the one number that survives every clue is the answer.

What kinds of clues appear?

Parity (even / odd), range (greater or less than a value), multiples (is or is not a multiple of a small number), the digit sum, and whether the number has two digits.

Can I print it as a worksheet?

Yes. Deduction supports the printable worksheet generator · the clues and numbered options print on paper with an answer key, since the whole puzzle is text.

How does my progress save?

Your best streak is stored locally in your browser. Sign in to sync it across devices.

演繹 · 消去法で数字を見つける · 日本語

A few clues describe one secret number · cross out every option that breaks a clue and the one left standing is the answer

A few clues describe one secret number · use elimination to pick the option that fits them all. JavaScript required.

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