# Concept derivation guides

299 concept teaching guides, separate from the 36,000 individual question derivations.

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Concept guide



## [Fermat modulo 7 and a composite boundary](/en/derivations/derivation-mko-fermat-little-theorem-01/?from=%2Fen%2Fderivations%2F%3Fq%3Dmko-fermat-little-theorem)

(-2)^6 is congruent to 1 modulo 7; for multiples of 7, only the congruence a^7≡a modulo 7 applies; passing a Fermat test does not prove primality.

Fermat's little theorem

derivation-mko-fermat-little-theorem-01





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