FACTORSLesson 6

Math Vocabulary

Factors:All the smaller numbers that go INTO a

given number

GCF:Greatest Common Factor (GCF)

The biggest small number that is shared between two given numbers

How to find factors…Start with the # and count backwards…

Which smaller numbers can the given # be ÷ by?

Find the factors:

10:10, 5, 2, 1

12:12, 6, 4, 3, 2, 1

20:20, 10, 5, 4, 2, 1

Finding Common Factors

Important!! All factors of a # include the given number (itself) AND 1

Example:

8:8, 4, 2, 1

15:15, 5, 3, 1

18:18, 9, 2, 1

Finding Common Factors

Common Factors:All the smaller #s

(factors) two numbers have in common (share)

Example:16:

16, 8, 4, 2, 1

20:20, 10, 5, 4, 2, 1

24:24, 12, 8, 6, 4, 3, 2, 1

Common factors: 4, 2, 1

Finding GCF

The GCF is…The biggest # two or more given #s

share

*(has to be equal to or smaller than the

smaller given #)

Example:10:

10, 5, 2, 1

40: 40, 20, 10, 8, 5, 4, 2, 1

GCF = 10

Practice

Find all the factors of

a) 24: 16: 30:

b) Name all common factors of 24,16 and 30

c) Name the GCF of 24, 16, and 30