math help

What is 36/4 + 9/12?

What is 36/4 + 9/12?

Here's how you add

36
4
+
9
12

Step 1

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

12 goes into 4 evenly, so we only need to multiply one term to get a common denominator.

Multiply 36 by 3, and get 108, then we multiply 4 by 3 and get 12.

36/4 times 3

This gives us a new problem that looks like so:

108
12
+
9
12

Step 2

Since our denominators match, we can add the numerators.

108 + 9 = 117

So what's the answer so far?

117
12

Step 3

Can this fraction be reduced?

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

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

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

117
12
÷ 3 =
39
4

Now, try the same number again.

Nope. Try the next prime number, 5...

No good. 5 is larger than 4. So we're done reducing.

Congratulations! Here's your final answer to 36/4 + 9/12

36
4
+
9
12
=
39
4
© 2014 Randy Tayler