How do you find the Gcf of given numbers?

Answer 1

Use one of the following three methods.

1) List some factors for both numbers, see which ones are common for the two. Probably it's easier to multiply the larger of the two numbers by 1, by 2, by 3, etc., and stop when you find a multiple that is also a multiple of the other number. This method is only practical for fairly small numbers.

2) Factor the numbers into prime factors. See which prime factors are shared among the two numbers. If a prime factor appears repeatedly, use the lower power as the common factor. Multiply all those prime factors together.

3) Use Euclid's algorithm. It is a bit more confusing at first, but it works for very high numbers, without the hassle of factoring them. Example: the greatest common factor of 14 and 10 is the same as the greatest common factor of 10 and 4; where 4 is the remainder of the division of 14 by 10.