Answer:
The LCM of two numbers is the least common multiple. You want to find the least possible number that is divisible by the two numbers. So, you can list the factors of the two numbers. If there are factors that are repeated, put the repeated factors to the side. With the remaining factors, multiply the factors by each other and the repeated factors.
For example, let's try to find the least common multiple between 10 and 15.
Factors of 10: 2 * 5
Factors of 15: 3 * 5
The repeated factor is 5.
2 and 3 are left over. 2 * 3 = 6. 6 * 5 = 30. So, that is the least common multiple.
The GCF of two numbers is the greatest common factor. You want to find the greatest factor that is included in both numbers. So, again, you can list the factors of the two numbers and find the greatest factor that is repeated between the two numbers.
For example, let's try to find the greatest common factor between 30 and 45.
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
Factors of 45: 1, 3, 5, 9, 15, 45
Between the two numbers, shared factors are 1, 3, 5, and 15. So, the greatest common factor is 15.
Hope this helps!
