math help

What is 99/7 + 6/8?

What is 99/7 + 6/8?

Let's add

99
7
+
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 99 by 8, and get 792, then we multiply 7 by 8 and get 56.

99/7 times 8

Do the same for the second term. We multiply 6 by 7, and get 42, then multiply 7 by 8 and get 56.

6/8 times 7

So now our fractions look like this:

792
56
+
42
56

Step 2

Since our denominators match, we can add the numerators.

792 + 42 = 834

So the answer is:

834
56

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:

834
56
÷ 2 =
417
28

Let's try dividing by that again...

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

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...

No good. 29 is larger than 28. So we're done reducing.

There you have it! Here's the final answer to 99/7 + 6/8

99
7
+
6
8
=
417
28
© 2014 Randy Tayler