# Factors and Multiples FACTORS & MULTIPLES Mrs. Walker 4th grade math FACTOR Factors are numbers that are multiplied 8 X 8 = 64

What does Find the factors mean? find all the numbers you can multiply together to get that number as the product.

EVERY number greater than 1 has the number 1 and itself as a factor. WHAT ARE THE FACTORS OF 27? Remember, you are being asked to find all the numbers that can be multiplied together to get the answer 27.

27: 1, 3, 9, 27 1 X 27 3X9 HINT: Always write factors from least to greatest. PRACTICE Find the factors: 1. 18 2. 24 3. 21

4. 52 COMMON FACTORS What 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? 16 1 X 16 2X8 4X4 Hint: Once you repeat a number youre done!! 16: 1, 2, 4, 8, 16 24

1 X 24 2 X 12 3X8 4X6 24: 1, 2, 3, 4, 6, 8, 12, 24 Common Factors: 1, 2, 4, 8 PRACTICE What are the common

factors of: 1. 6 & 9 2. 24 & 48 3. 25 & 45 GREATEST COMMON FACTOR The greatest factor that both numbers have in common. GCF = Greatest Common

Factor FIND THE GCF 9 1x9 3x3 12 1 x 12 2x6 3x4

9 : 1,3,9 12: 1,2,3,4,6,12 PRACTICE Find the GCF: 1. 2. 12 & 26 9 & 21

WHITE BOARD PRACTICE List the factors: 1. 36 2. 18 3. 27 List the common factors: 4. 18, 22 5. 52, 36

6. 14, 9 List the GCF: 7. 25, 40 8. 30, 42 INDEPENDENT PRACTICE Math Book Pg. 112 #s 11-18 And Pg. 113 #s 36-43

MULTIPLES A multiple is the product of a given whole number and another whole 8 1 1 20,24 4 4 number. : , , 2, 6,

MULTIPLE Multiples form a skip counting pattern! 5: 5, 10, 15, 20, 25, LIST THE MULTIPLES OF 7 UP TO 42

7:7 1 2 2835,42 , 4, 1, , You use the INVERSE OPERATION of multiplication to see if a specific number is a multiple of the given number.

Example: Is 108 a multiple of 6? PRACTICE 1. 2. 3. 4. Find the first 10 multiples of 3 Find the first 6 multiples of 8

Is 40 a multiple of 8? Why? Is 63 a multiple of 5? Why? COMMON MULTIPLE A multiple that 2 or more numbers have in common. Example: Find the first 3 common multiples of 3 and 6. 3 3 6 9,1 15,18 12,24 30,36

6 12 6 , , : CM: 6, 12, 18 : , , 8, ,

IS 36 A COMMON MULTIPLE OF 6 AND 9? What strategy would you use? Thats Right! Division 36 6= ? 36 9=? Yes! 36 is a common multiple of 6 and 9. PRACTICE 1. Is 42 a common multiple of 6

and 9? List 10 multiples of each number and circle the common multiples. 2. 3 and 6 3. 4 and 12 4. 2 and 5 LEAST COMMON MULTIPLE The smallest multiple that 2 or more numbers have in common.

LCM = Least Common Multiple Example: Find least common multiples of 6 and 8. 6 8 : : LCM: 24 6 121 2430,36

24, 8 , 3240,48 , ,168, , , , WHITE BOARD PRACTICE List the first 5 multiples of each number.

1. 2 2. 4 3. 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 19-26 And

MB pg. 113 #s 44-52