math help

What is 15/60 + 4/12?

What is 15/60 + 4/12?

Here's how to add

15
60
+
4
12

Step 1

Our denominators (bottom numbers) don't match, so we can't add yet.

60 goes into 12 evenly, so we only need to multiply one term to get a common denominator.

Multiply 4 by 5, and get 20, then we multiply 12 by 5 and get 60.

4/12 times 5

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

15
60
+
20
60

Step 2

Since our denominators match, we can add the numerators.

15 + 20 = 35

Answer:

35
60

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...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

35
60
÷ 5 =
7
12

Now, try the same number again.

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

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

No good. 11 is larger than 7. So we're done reducing.

Congratulations! Here's your final answer to 15/60 + 4/12

15
60
+
4
12
=
7
12
© 2014 Randy Tayler