math help

What is 100/72 + 1/9?

What is 100/72 + 1/9?

Here's how to add

100
72
+
1
9

Step 1

We have to make sure the denominators are equal.

Since 9 is evenly divided by 72, we can multiply just one term to get a common denominator.

Multiply 1 by 8, and get 8, then we multiply 9 by 8 and get 72.

1/9 times 8

The problem now has new fractions to add:

100
72
+
8
72

Step 2

Since our denominators match, we can add the numerators.

100 + 8 = 108

The sum we get is

108
72

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

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

108
72
÷ 2 =
54
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:

54
36
÷ 2 =
27
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:

27
18
÷ 3 =
9
6

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

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

9
6
÷ 3 =
3
2

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

No good. 3 is larger than 2. So we're done reducing.

And we're done! Here's the final answer to 100/72 + 1/9

100
72
+
1
9
=
3
2
© 2014 Randy Tayler