math help

What is 21/11 + 8/9?

What is 21/11 + 8/9?

Here's how to add

21
11
+
8
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 21 by 9, and get 189, then we multiply 11 by 9 and get 99.

21/11 times 9

Now for the second term. You multiply 8 by 11, and get 88, then multiply 11 by 9 and get 99.

8/9 times 11

This gives us a new problem that looks like so:

189
99
+
88
99

Step 2

Since our denominators match, we can add the numerators.

189 + 88 = 277

That gives us an answer of

277
99

Step 3

Can this fraction be reduced?

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

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

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...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

Nope. Try the next prime number, 83...

Nope. Try the next prime number, 89...

Nope. Try the next prime number, 97...

Nope. Try the next prime number, 101...

No good. 101 is larger than 99. So we're done reducing.

Congratulations! Here's your final answer to 21/11 + 8/9

21
11
+
8
9
=
277
99
© 2014 Randy Tayler