FACTORS & MULTIPLES

Mrs. Walker4th grade math

FACTORFactors are

numbers that are multiplied

8 X 8 = 64

…find all the numbers you can multiply

together to get that number as the product.

What does

“Find the factors”

mean?

EVERY number greater than 1

has the number 1 and itself as a

factor.

WHAT ARE THE FACTORS OF 27?

27:1 X 273 X 9

27: 1, 3, 9, 27HINT:

Always write factors from least to greatest.

Remember, you are being asked to find all the numbers that can be multiplied together to get the answer 27.

PRACTICEFind the factors:1. 182. 243. 214. 52

COMMON FACTORSWhat does COMMON mean?What does FACTORS mean?

So….. COMMON FACTORS are:Factors that two or more

numbers have in common

WHAT ARE THE COMMON FACTORS OF 16 AND 24?

161 X 16

2 X 84 X 4

241 X 24 2 X 12 3 X 8 4 X 6 Hint: Once you repeat a

number you’re done!!

16: 1, 2, 4, 8, 16 24: 1, 2, 3, 4, 6, 8, 12, 24

Common Factors: 1, 2, 4, 8

PRACTICEWhat are the common factors of:1. 6 & 92. 24 & 483. 25 & 45

GREATEST COMMON FACTORThe greatest factor that both numbers have in

common.

GCF = Greatest Common Factor

FIND THE GCF9

1 x 9 3 x 3

9 : 1,3,9

121 x 12 2 x 6 3 x 4

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

PRACTICEFind the GCF:1. 12 & 262. 9 & 21

WHITE BOARD PRACTICE

List the factors:1. 362. 183. 27List the common factors:4. 18, 225. 52, 366. 14, 9List the GCF:7. 25, 408. 30, 42

INDEPENDENT PRACTICEMath Book

Pg. 112 #s 11-18And

Pg. 113 #s 36-43

MULTIPLEMultiples form a skip

counting pattern!5: 5, 10, 15, 20, 25, 30…

Example:15 is a multiple of 5 because it is made up of 3 groups of

5.

Use the inverse operation of

multiplication,DivisionTo find

multiples!

LIST THE MULTIPLES OF 7 UP TO 42

7: 7, 14, 21, 28, 35, 42

IS 108 A MULTIPLE OF 6?Strategy: Use a division

number sentence.108 ÷ 6=

(if the quotient is a whole number then 6 is a multiple.)

Solution: Yes, 108 is a multiple of 6 because 108

÷ 6= 18

PRACTICEFind 10 multiples of:

1. 3

2. 8

3. 11

COMMON MULTIPLEA multiple that 2 or

more numbers have in common.

IS 36 A COMMON MULTIPLE OF 6 AND 9?What strategy would you

use?That’s Right! Division

36 ÷ 6= ?36 ÷ 9=?

Yes, 36 is a common multiple of 6 and 9.

PRACTICE1. Is 42 a common multiple of 6 and 9?

List 10 multiples of each number and circle the common multiples.2. 3,63. 4, 124. 2, 5

LEAST COMMON MULTIPLE

The lowest multiple that both numbers have in common.

LCMEX. What is the LCM of 12 and 24?

Strategy: List the multiples of 12 and 24.12:12,24

24: 24

WHITE BOARD PRACTICEList the first 5 multiples of each number.1. 22. 43. Name the LCM of the following numbers:20 and 5

4. How many common multiples less than 50 do 8 and 9 have? Name them

INDEPENDENT PRACTICE

MB pg. 112 #s 19-26And

MB pg. 113 #s 44-52