math help

What is 4/12 + 6/9?

What is 4/12 + 6/9?

This is how we add

4
12
+
6
9

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 4 by 9, and get 36, then we multiply 12 by 9 and get 108.

4/12 times 9

Now for the second term. You multiply 6 by 12, and get 72, then multiply 12 by 9 and get 108.

6/9 times 12

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

36
108
+
72
108

Step 2

Since our denominators match, we can add the numerators.

36 + 72 = 108

That gives us the sum, which is

108
108

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:

108
108
÷ 2 =
54
54

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

54
54
÷ 2 =
27
27

Now, try the same number again.

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

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

27
27
÷ 3 =
9
9

Now, try the same number again.

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

9
9
÷ 3 =
3
3

Now, try the same number again.

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

3
3
÷ 3 =
1
1

Now, try the same number again.

No good. 3 is larger than 1. So we're done reducing.

Congratulations! Here's your final answer to 4/12 + 6/9

4
12
+
6
9
=
1
1
= 1
© 2014 Randy Tayler