 What is 6/10 + 6/9? 6 10
+
 6 9

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 6 by 9, and get 54, then we multiply 10 by 9 and get 90. Now for the second term. You multiply 6 by 10, and get 60, then multiply 10 by 9 and get 90. We now have a new problem, that looks like this:

 54 90
+
 60 90

Step 2

Since our denominators match, we can add the numerators.

54 + 60 = 114

That gives us the sum, which is

 114 90

Step 3

Now, do we need to simplify this fraction?

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

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

 114 90
÷ 2 =
 57 45

Now, try the same number again.

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

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

 57 45
÷ 3 =
 19 15

Now, try the same number again.

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...

No good. 17 is larger than 15. So we're done reducing.