math help

What is 100/72 + 4/9?

What is 100/72 + 4/9?

This is how we add

100
72
+
4
9

Step 1

We have to make sure the denominators are equal.

72 goes into 9 evenly, so we only need to multiply one term to get a common denominator.

Multiply 4 by 8, and get 32, then we multiply 9 by 8 and get 72.

4/9 times 8

This gives us a new problem that looks like so:

100
72
+
32
72

Step 2

Since our denominators match, we can add the numerators.

100 + 32 = 132

That gives us an answer of

132
72

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

132
72
÷ 2 =
66
36

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

66
36
÷ 2 =
33
18

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

33
18
÷ 3 =
11
6

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. 7 is larger than 6. So we're done reducing.

And we're done! Here's the final answer to 100/72 + 4/9

100
72
+
4
9
=
11
6
© 2014 Randy Tayler