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Every positive integer can be broken down into powers of two. Can you spot the shortcut to a special kind of sum?

Successfully pulling off the tablecloth trick can require a lot of trial and error, spilt drinks, and broken glass. Can you master it a smarter way?

Sometimes, we can rearrange the numbers in a grid so that every row and column has the same sum. Instead, could we make this sum by replacing numbers with 0s?

In a tracing puzzle, you canâ€™t lift your writing tool or go over a segment twice. This triangle is impossible, but is tracing it impossible, too?

Similar triangles can often hide in unexpected places. Could they help with this challenge?

In multi-level mobiles, weights on one level can affect another. Can you salvage this mobile, or is it unavoidably unbalanced?

With some reasoning, you can find a shortcut for the final digit of this multiplication problem.

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