Factors and Multiples

Factors & MultiplesMrs. Walker4th grade math

FactorFactors are numbers that are multiplied8 X 8 = 64

find all the numbers you can multiply together to get that number as the product.

What does Find the factorsmean?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

HINT: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 27.1, 3, 9, 27practiceFind the factors:18242152

Common FactorsWhat does COMMON mean?What does FACTORS mean?So.. COMMON FACTORS are:Factors that two or more numbers have in commonWhat 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 youre done!!

16: 1, 2, 4, 8, 1624: 1, 2, 3, 4, 6, 8, 12, 24 Common Factors: 1, 2, 4, 8PracticeWhat are the common factors of:6 & 924 & 4825 & 45Greatest Common FactorThe greatest factor that both numbers have in common.

GCF = Greatest Common FactorFind the GCF91 x 9 3 x 3

9 : 1,3,9121 x 12 2 x 6 3 x 4

12: 1,2,3,4,6,12PracticeFind the GCF:12 & 269 & 21White board PracticeList the factors:361827List the common factors:18, 2252, 3614, 9List the GCF:25, 4030, 42

Independent PracticeMath BookPg. 112 #s 11-18AndPg. 113 #s 36-43MultiplesA multiple is the product of a given whole number and another whole number.

4,8,12,16,20,244:MultipleMultiples form a skip counting pattern!

5: 5, 10, 15, 20, 25, 30

List the multiples of 7 up to 427:7,14,21,28,35,42You use the INVERSE OPERATIONof multiplication to see if a specific number is a multiple of the given number.

Example:Is 108 a multiple of 6?

PracticeFind the first 10 multiples of 3Find the first 6 multiples of 8Is 40 a multiple of 8? Why?Is 63 a multiple of 5? Why?

Common MultipleA multiple that 2 or more numbers have in common.

Example: Find the first 3 common multiples of 3 and 6.

CM: 6, 12, 18

3,6,9,12,15,183:6,12,18,24,30,366: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.Practice1. Is 42 a common multiple of 6 and 9?

List 10 multiples of each number and circle the common multiples.2. 3 and 63. 4 and 124. 2 and 5Least Common MultipleThe smallest multiple that 2 or more numbers have in common.

LCM = Least Common Multiple

Example: Find least common multiples of 6 and 8.

LCM: 24

6,12,18,24,30,366:8,16,24,32,40,488:White board PracticeList the first 5 multiples of each number.243. 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 PracticeMB pg. 112 #s 19-26AndMB pg. 113 #s 44-52