math help

What is 9/12 + 8/11?

What is 9/12 + 8/11?

Here's how you add

9
12
+
8
11

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 9 by 11, and get 99, then we multiply 12 by 11 and get 132.

9/12 times 11

Do the same for the second term. We multiply 8 by 12, and get 96, then multiply 12 by 11 and get 132.

8/11 times 12

So now our fractions look like this:

99
132
+
96
132

Step 2

Since our denominators match, we can add the numerators.

99 + 96 = 195

So the answer is:

195
132

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing 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:

195
132
÷ 3 =
65
44

Now, try the same number again.

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

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

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

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

No good. 47 is larger than 44. So we're done reducing.

Congratulations! Here's your final answer to 9/12 + 8/11

9
12
+
8
11
=
65
44
© 2014 Randy Tayler