 # What is 7/10 + 2/4? This is how you add

 7 10
+
 2 4

## 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 7 by 4, and get 28, then we multiply 10 by 4 and get 40. Now for the second term. You multiply 2 by 10, and get 20, then multiply 10 by 4 and get 40. We now have a new problem, that looks like this:

 28 40
+
 20 40

## Step 2

Since our denominators match, we can add the numerators.

28 + 20 = 48

That gives us the sum, which is

 48 40

## 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:

 48 40
÷ 2 =
 24 20

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:

 24 20
÷ 2 =
 12 10

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:

 12 10
÷ 2 =
 6 5

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...

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 7/10 + 2/4

 7 10
+
 2 4
=
 6 5
© 2014 Randy Tayler