Divisibility Rules
Factors/Misc
Square Number
&
Even/Odd
Common Factors/Prime Factorization Tree
GCF
100
Every number is divisible by ___.
1
100
List all the factors of 21.
1,3,7,21
100

Even/Odd 54+63

ODD

100

These are the common factors between 21 and 32

21= 1,3,7,21     

32= 1,2,4,8,16,32

Same factors 1

100
If two numbers have nothing in common from their factor trees, what is their GCF?
1
200
Is 456 divisible by 2? Why or why not?
Yes because it ends in 6 (or ends in an even number).
200

List all the factors of 13

1,13

200

Even/Odd   102*3

EVEN

200

These are the common factors between 18 and 24

18: 1,2,3,6,9,18

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

Common Factors: 1,2,3,6

200
Find the GCF of 5 and 20.
5, 20=2x2x5, GCF=5
300
Is 794 divisible by 5? Why or why not?
No because it doesn't end in 0 or 5.
300

Congruent means 

Identical or the same shape and size

300

The missing square number consecutive of:

121, 144, ____, 196, 225

169

300

Make Factor Tree to find the prime factorization of 50 and 75

50: 2,5,5

75: 3,5,5

Prime Factorization is 5x5 = 25

300
Find the GCF of 12 and 18.
12=2x2x3, 18=2x3x3, GCF=2x3=6
400

Is 120 divisible by 6? Why or why not?

Yes because the last digit (0) is even (divisible by 2), and 1 + 2 + 0 = 3 (divisible by 3). Therefore, 120 is divisible by 6. 

400
List all the factors of 32.
1,2,4,8,16,32
400

True/False: This list is all square numbers

1,4,9,16,25

True

400
Find the prime factorization of 50. (Make a factor tree and write out your answer)
50=2x5x5
400
Find the GCF of 7 and 11.
GCF=1
500
Is 562 divisible by 3? Why or why not?
No because 5+6+2=13 which is not divisible by 3.
500

Similar means

Same but different size

500

True/False: This list is all square numbers

1, 3, 9,27,81 

False

500
Find the prime factorization of 81. (Make a factor tree and write out your answer)
81=3x3x3x3
500
Find the GCF of 8 and 28.
8=2x2x2, 28=2x2x7, GCF=2x2=4
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