math help

What is 21/33 + 6/8?

What is 21/33 + 6/8?

Here's how you add

21
33
+
6
8

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 21 by 8, and get 168, then we multiply 33 by 8 and get 264.

21/33 times 8

Do the same for the second term. We multiply 6 by 33, and get 198, then multiply 33 by 8 and get 264.

6/8 times 33

So now our fractions look like this:

168
264
+
198
264

Step 2

Since our denominators match, we can add the numerators.

168 + 198 = 366

Now we have an answer.

366
264

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...

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

366
264
÷ 2 =
183
132

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

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

183
132
÷ 3 =
61
44

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

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

And we're done! Here's the final answer to 21/33 + 6/8

21
33
+
6
8
=
61
44
© 2014 Randy Tayler