math help

What is 21/11 + 6/8?

What is 21/11 + 6/8?

Here's how we add

21
11
+
6
8

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 21 by 8, and get 168, then we multiply 11 by 8 and get 88.

21/11 times 8

Do the same for the second term. We multiply 6 by 11, and get 66, then multiply 11 by 8 and get 88.

6/8 times 11

The problem now has new fractions to add:

168
88
+
66
88

Step 2

Since our denominators match, we can add the numerators.

168 + 66 = 234

The sum we get is

234
88

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

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

234
88
÷ 2 =
117
44

Now, try the same number again.

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...

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

Congratulations! Here's your final answer to 21/11 + 6/8

21
11
+
6
8
=
117
44
© 2014 Randy Tayler