# Primary Mathematics/Factors and Primes

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## Factors and Primes[edit | edit source]

**Factors** are numbers that you can multiply together to get another number.
For example: 8 and 11 are factors of 88 as 8 x 11 = 88.
Similarly, 10 is a factor of 100 as 10 x 10 is 100.

**Prime factors** are factors which are **prime numbers**.

55 = 5 x 11 100 = 2 x 5 x 2 x 5

Because 2, 5, and 11 cannot be divided by any number but 1 and itself, these numbers are called *prime*. Prime numbers are an important part of mathematics, and the problem of factoring large numbers into primes remains fundamental to the study of computer science.
Factoring a number like 64 often requires more than one step:

64 = 2 x 32 (32 is not prime) or = 2 x 2 x 16 (16 is not prime) or = 2 x 2 x 2 x 8 (8 is not prime) or = 2 x 2 x 2 x 2 x 4 (4 is not prime) or = 2 x 2 x 2 x 2 x 2 x 2