What is 1/9 + 1/8?

Here's how you add

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

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

Now for the second term. You multiply 1 by 9, and get 9, then multiply 9 by 8 and get 72.

We now have a new problem, that looks like this:

Step 2

Since our denominators match, we can add the numerators.

8 + 9 = 17

Answer:

Step 3

Now, do we need to simplify this fraction?

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

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

No good. 19 is larger than 17. So we're done reducing.

Congratulations! Here's your final answer to 1/9 + 1/8