How do you find the GCF of numbers?

Answer 1

To find the gcf, write the factors for each of the numbers you are working with, and find the highest common number. For example, take 12 & 64:

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

64: 1, 2, 4, 8, 16, 32, 64

The gcf is 4

Answer 2

The 'rule' is that you must find the LARGEST number or algebraic expression that divides evenly (no remainder) into both given numbers or expressions. This can be done by 'trial and error' using your knowledge of multiplication facts (tables) or it can be done thru a process of factoring and using common factors from both.

Answer 3

To find the greatest common factor of two numbers:

-- Make a list of all the factors of the first number. (Don't forget ' 1 ' and the number itself.)

-- Make a list of all the factors of the second number. (Don't forget ' 1 ' and the number itself.)

-- Make a third list, of only the factors that are on both of the first two lists. (Don't forget ' 1 '.)

-- The largest number on the third list is the gcf of the original two numbers.

' 1 ' should always be there, and it's possible that it could be the only thing there.

For example, the gcf of 197 and 463 is ' 1 ' .

Answer 4

Example: 30 and 42
Factor them.
2 x 3 x 5 = 30
2 x 3 x 7 = 42
Select the common factors.
2 x 3 = 6, the GCF

Answer 5

It's the lowest number of each common variable.

The GCF of x2y3z4 and x4y2z3 is x2y2z3

Answer 6

Example: 30 and 42

Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Select the common factors.

2 x 3 = 6, the GCF

Answer 7

Example: 30 and 42

Step one: Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Step two: Select the common factors.

2 x 3 = 6, the GCF.