Creating convincing arguments or "proofs" to show that statements are always true is a key mathematical skill.

The problems in this feature offer students the chance to identify number patterns, make conjectures and create convincing mathematical proofs.

Many of the problems in this feature include proof sorting activities which challenge students to rearrange statements in order to recreate clear, rigorous proofs. These tasks aim to introduce students to the formality and logic of mathematical proof.

The last day for students to send in their solutions to the live problems is Monday 31 January.

Plus magazine has a selection of interesting articles about proofs here.

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Take three consecutive numbers and add them together. What do you notice?

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How many sets of three consecutive odd numbers can you find, in which all three numbers are prime?

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Is there a quick and easy way to calculate the sum of the first 100 odd numbers?

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What can we say about all the primes which are greater than 3?

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If you take four consecutive numbers and add them together, the answer will always be even. What else do you notice?

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Take four consecutive whole numbers. Multiply the first and last numbers together. Multiply the middle pair together. What do you notice?

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$40$ can be written as $7^2 - 3^2.$ Which other numbers can be written as the difference of squares of odd numbers?

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Which numbers cannot be written as the sum of two or more consecutive numbers?

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Can you use Proof by Induction to establish what will happen when you add more and more odd numbers?

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Here are a few questions taken from the Test of Mathematics for University Admission (or TMUA).

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Can you work through these direct proofs, using our interactive proof sorters?

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These proofs are wrong. Can you see why?