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Ships within 48 hours · Estimated delivery Sep 2 - Sep 7
Pay in 4 interest-free payments of $7.69 Learn more
Ships within 48 hours · Estimated delivery Sep 2 - Sep 7
Different hardwoods used to make the pieces
Now everyone has contributed 1 number
completing all three rules at once
Ready to challenge your mind or gift someone a custom wooden puzzle box
Fun and Challenging Puzzle: Unlock the hidden compartment using a clever mechanism
Order 21 Perfect Square Puzzle | Mathematical Brain Teaser large wood puzzle Different hardwoods used to makeDiscover the beauty of geometric dissections with the Order 21 Perfect Square Puzzle. Based on a groundbreaking mathematical discovery by A. J. W. Duijvestijn in 1978, this unique puzzle challenges you to arrange 20 wooden squares inside a frame, leaving an opening for the smallest 21st square, which is laser engraved on the frame. A Historic Mathematical Challenge This puzzle represents the only known perfect square dissection of order 21, an