math help

What is 99/7 + 4/8?

What is 99/7 + 4/8?

This is how to add

99
7
+
4
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 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 4 by 7, and get 28, then multiply 7 by 8 and get 56.

4/8 times 7

The problem now has new fractions to add:

792
56
+
28
56

Step 2

Since our denominators match, we can add the numerators.

792 + 28 = 820

The sum we get is

820
56

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:

820
56
÷ 2 =
410
28

Now, try the same number again.

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

410
28
÷ 2 =
205
14

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...

No good. 17 is larger than 14. So we're done reducing.

Congratulations! Here's your final answer to 99/7 + 4/8

99
7
+
4
8
=
205
14
© 2014 Randy Tayler