math help

What is 11/12 + 1/9?

What is 11/12 + 1/9?

Here's how you add

11
12
+
1
9

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 11 by 9, and get 99, then we multiply 12 by 9 and get 108.

11/12 times 9

Now for the second term. You multiply 1 by 12, and get 12, then multiply 12 by 9 and get 108.

1/9 times 12

This gives us a new problem that looks like so:

99
108
+
12
108

Step 2

Since our denominators match, we can add the numerators.

99 + 12 = 111

That gives us an answer of

111
108

Step 3

Can this fraction be reduced?

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

Nope! So now we try the next greatest prime number, 3...

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

111
108
÷ 3 =
37
36

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

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

There you have it! Here's the final answer to 11/12 + 1/9

11
12
+
1
9
=
37
36
© 2014 Randy Tayler