math help

What is 53/9 + 3/12?

What is 53/9 + 3/12?

Here's how to add

53
9
+
3
12

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 53 by 12, and get 636, then we multiply 9 by 12 and get 108.

53/9 times 12

Now for the second term. You multiply 3 by 9, and get 27, then multiply 9 by 12 and get 108.

3/12 times 9

This gives us a new problem that looks like so:

636
108
+
27
108

Step 2

Since our denominators match, we can add the numerators.

636 + 27 = 663

So what's the answer so far?

663
108

Step 3

Can this fraction be reduced?

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

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:

663
108
÷ 3 =
221
36

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. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. 37 is larger than 36. So we're done reducing.

And we're done! Here's the final answer to 53/9 + 3/12

53
9
+
3
12
=
221
36
© 2014 Randy Tayler