math help

What is 99/7 + 8/10?

What is 99/7 + 8/10?

Here's how you add

99
7
+
8
10

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 10, and get 990, then we multiply 7 by 10 and get 70.

99/7 times 10

Do the same for the second term. We multiply 8 by 7, and get 56, then multiply 7 by 10 and get 70.

8/10 times 7

So now our fractions look like this:

990
70
+
56
70

Step 2

Since our denominators match, we can add the numerators.

990 + 56 = 1046

Now we have an answer.

1046
70

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:

1046
70
÷ 2 =
523
35

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...

No good. 37 is larger than 35. So we're done reducing.

Congratulations! Here's your final answer to 99/7 + 8/10

99
7
+
8
10
=
523
35
© 2014 Randy Tayler