 What is 6/10 + 7/8? 6 10
+
 7 8

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 8, and get 48, then we multiply 10 by 8 and get 80. Now for the second term. You multiply 7 by 10, and get 70, then multiply 10 by 8 and get 80. We now have a new problem, that looks like this:

 48 80
+
 70 80

Step 2

Since our denominators match, we can add the numerators.

48 + 70 = 118

That gives us the sum, which is

 118 80

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:

 118 80
÷ 2 =
 59 40

Now, try the same number again.

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...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

No good. 41 is larger than 40. So we're done reducing.