Factors

In mathematics, a factor is a number that divides another number completely without leaving a remainder. Understanding factors is essential for various topics in math, including algebra and number theory.

Here’s a simple breakdown of the concept:

  • A factor of a number is an integer that divides the number evenly.
    • For example, 2 is a factor of 8 because 8 ÷ 2 = 4 with no remainder.
  • To find factors, you can start by testing numbers from 1 up to the number itself to see which ones divide it evenly.
  • Example: To find the factors of 12, test numbers 1, 2, 3, 4, 6, and 12:
    • 12 ÷ 1 = 12 (Factor)
    • 12 ÷ 2 = 6 (Factor)
    • 12 ÷ 3 = 4 (Factor)
    • 12 ÷ 4 = 3 (Factor)
    • 12 ÷ 6 = 2 (Factor)
    • 12 ÷ 12 = 1 (Factor)
  • So, the factors of 12 are 1, 2, 3, 4, 6, and 12.
  • Prime factors are factors that are prime numbers. For instance, the prime factors of 12 are 2 and 3, since 12 = 2 × 2 × 3.
  • Factor pairs are two numbers that multiply together to give the original number.
    • For 12, the factor pairs are (1, 12), (2, 6), and (3, 4).
  • The GCF is the largest factor that two or more numbers share.
    • For example, the GCF of 12 and 18 is 6.
  • 5
  • 27
  • 2
  • 3

Divide all the numbers into 9, and see which one divides evenly.

9 ÷ 5 = 1 R4   No
9 ÷ 27 = 0 R9   No
9 ÷ 2 = 4 R1   No
9 ÷ 3 = 3 R0   Yes, 3 divides evenly

3 divides evenly into 9, so 3 is a factor.

  • 7
  • 5
  • 4
  • 3

Divide all the numbers into 16, and see which one divides evenly.

16 ÷ 7 = 2 R2   No
16 ÷ 5 = 3 R1   No
16 ÷ 4 = 4 R0   Yes, 4 divides evenly
16 ÷ 3 = 5 R1   No

4 divides evenly into 16, so 4 is a factor.

  • 3
  • 6
  • 2
  • 4

Divide all the numbers into 10, and see which one divides evenly.

10 ÷ 3 = 3 R1   No
10 ÷ 6 = 1 R4   No
10 ÷ 2 = 5 R0   Yes, 2 divides evenly
10 ÷ 4 = 2 R2   No

2 divides evenly into 10, so 2 is a factor.

let’s practice!