Working backwards is an important part of mathematical problem solving. In this feature, we share problems that encourage students to think about the relationships between processes and their inverses.

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What is the smallest number of answers you need to reveal in order to work out the missing headers?

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Try entering different sets of numbers in the number pyramids. How does the total at the top change?

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When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...

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Can you find the hidden factors which multiply together to produce each quadratic expression?

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Can you match the charts of these functions to the charts of their integrals?

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A function pyramid is a structure where each entry in the pyramid is determined by the two entries below it. Can you figure out how the pyramid is generated?