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# Prime factorization and factor trees (6th grade math)

I show several examples of building a factor tree and finding the prime factorization of various numbers. In this lesson we focus on factoring three-digit numbers. The starting point for factoring is to find a divisor of the number. You can use the basic divisibility tests for starters, and beyond that, test-divide (long division) to check if the number is divisible by another.

The sieve of Eratosthenes (for finding primes)

Least common multiple

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