What is 100/72 + 7/9?

This is how to add

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 7 by 8, and get 56, then we multiply 9 by 8 and get 72.

So now our fractions look like this:

Step 2

Since our denominators match, we can add the numerators.

100 + 56 = 156

Now we have an answer.

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

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:

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:

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:

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 + 7/9