How do you show the greatest common factor 40 in a Venn diagram?

Answer 1

Write the numbers in their prime factorisations (with each prime repeated as many times as necessary)

write the common primes in the overlapping bis of the venn diagram and write the non-common primes in their respective separate parts of the venn diagram.

eg gcf(240, 280):

240 = 2 x 2 x 2 x 2 x 3 x 5

280 = 2 x 2 x 2 x 5 x 7

For the 240 circle, write 2 and 3 in the non-overlapping bit (ie the non-common primes)

For the 280 circle, write 7 in the non-overlapping bit (ie the non-common prime)

In the overlapping bit write 2, 2, 2 and 5 (ie the common primes, in bold above)

The gcf is the product of the primes in the overlapping bit:

gcf = 2 x 2 x 2 x 5 = 40

Answer 2

Put the factors of one number in the left circle, put the factors of the other number in the right circle. Put any numbers that are the same in the space where the circles intersect. The largest of these is the GCF.

Answer 3

I may be the wrong person to answer this, but I've never found a Venn diagram particularly useful in finding a GCF. It's just a way to display the result after you already know what it is. Put the factors of one number in the left circle, the factors of the other number in the right circle. Put the common factors in the space where they intersect. The largest of these is the GCF. But you can list the factors on any piece of paper and don't need the circles. There are much more efficient ways to achieve this.

Answer 4

Put 16 in the left circle.
Put 3, 6, 12 and 24 in the right circle.
Put 1, 2, 4 and 8 in the center where they intersect.
The largest of these is 8, the GCF.

Answer 5

Factor them.

2 x 2 x 2 = 8

2 x 2 x 2 x 2 = 16

Select the common factors.

2 x 2 x 2 = 8, the GCF

Answer 6

Put 16 in the left circle, 3, 6, 12 and 24 in the right circle, and 1, 2, 4, 8 in the middle.

Answer 7

Draw two interlocking circles. Put 7, 14 and 28 in the left circle. Put 3, 6, 8, 9, 12, 18, 24, 36 and 72 in the right circle. Put 1, 2 and 4 in the space where they intersect. The GCF is 4.