FACTORS AND MULTIPLES
To find the prime factorization of a number, keep breaking it down into factors of the number until you are left with only prime
numbers.
To find the prime factorization of 168:
To find the greatest common factor (GCF) of two integers, break down both integers into their prime factorizations and mulitply
all prime factors they have in common.
If you’re looking for the greatest common factor of 40 and 130, first identify the prime factors of each integer.
Next, see what prime factors the two numbers have in common and then multiply these common factors.
Both integers share two 2s and 5, so the GCF is 2 × 2 × 5 or 20.
FACTOR CHARTS
Use a T-chart to organize the factors of a given number. Example: