Logic games and reasoning problems
Rule out possibilities, test hypotheses and find a strategy you can explain.
A way to begin
Separate facts from assumptions. A drawing, table or small experiment can clarify a problem. Help is optional; studying a solution is another way to learn.
No registration needed. Each game explains its rules; accessibility settings are in Settings. Rest, switch activities or return whenever you wish.
Reason, test and prove
Intermediate to very difficult problems. Look for an argument that rules out alternatives, as well as an answer.
Nine coins, two weighings
Eight coins weigh the same; one is heavier. Find it with just two comparisons.
3D room✓ Solved
Four unmarked vessels
Split nine litres into three equal quantities without estimating.
Interactive board✓ Solved
Twelve coins, unknown weight
One coin may be heavier or lighter. Design three weighings to identify both facts.
Interactive board✓ SolvedRelated pastimes
Sudoku
Nine numbers. One satisfying challenge.
Nonogram
Draw with logic. Reveal the hidden picture.
Secret code
Four symbols. Ten tries. Follow the clues.
Towers of Hanoi
Three towers. One elegant solution.
Binary puzzle
Zeros and ones. Everything finds its balance.
Lights out
One tap changes everything.
Introductory practice
From play to reflection
After playing, describe your strategy and what you would change. Improving at a game does not itself demonstrate general changes in memory or intelligence.
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