Factors and primes, worked out

The Factor Tree

Every whole number is built out of primes. Find all the factors in pairs, grow a factor tree down to its primes, test whether a number is prime, find the GCF and LCM, and use the divisibility rules — with the reason for every step.

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The work

Say it out loud

    Whole numbers up to 1,000,000, every step written out. Need a division done out in full? Work it on ÷, or check a product on ×.