Write the prime factorization of 6
3 and 2
Find the GCF of 3 and 9
3
Simplify
3/6
1/2
Find the GCF of 20 and 40
has to end in a 0, 2, 4, 6, or 8
Write the prime factorization of 20
5, 2, 2
Find the GCF of 15 and 25
5
Simplify
3/12
1/4
Find the GCF of 10 and 20
10
Divisibility rule for 3
If you add the digits of the number and the sum is divisible by 3, then the number is divisible by 3
Write the prime factorization of 100
5, 5, 2, 2
Find the GCF of 45 and 75
15
Simplify
15/60
1/4
Find the GCF 60 and 120
60
has to end in a 5 or 0
Write the prime factorization of 152
19, 2, 2, 2
5
Simplify
36/60
3/5
Find the GCF of 110 and 240
10
Divisibility Rule for 9
If you add the digits and the sum is divisible by 9, then the number is divisible by 9
Write the prime factorization of 243
3, 3, 3, 3, 3
Find the GCF of 121 and 143
11
Simplify
56/60
14/15
Find the GCF of 352 and 422
2
Divisibility rule for 6
Is the number is even and divisible by 3