math help

What is 9/100 + 7/8?

What is 9/100 + 7/8?

Here's how you add

9
100
+
7
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 9 by 8, and get 72, then we multiply 100 by 8 and get 800.

9/100 times 8

Do the same for the second term. We multiply 7 by 100, and get 700, then multiply 100 by 8 and get 800.

7/8 times 100

So now our fractions look like this:

72
800
+
700
800

Step 2

Since our denominators match, we can add the numerators.

72 + 700 = 772

Now we have an answer.

772
800

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:

772
800
÷ 2 =
386
400

Now, try the same number again.

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

386
400
÷ 2 =
193
200

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...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

Nope. Try the next prime number, 83...

Nope. Try the next prime number, 89...

Nope. Try the next prime number, 97...

Nope. Try the next prime number, 101...

Nope. Try the next prime number, 103...

Nope. Try the next prime number, 107...

Nope. Try the next prime number, 109...

Nope. Try the next prime number, 113...

Nope. Try the next prime number, 127...

Nope. Try the next prime number, 131...

Nope. Try the next prime number, 137...

Nope. Try the next prime number, 139...

Nope. Try the next prime number, 149...

Nope. Try the next prime number, 151...

Nope. Try the next prime number, 157...

Nope. Try the next prime number, 163...

Nope. Try the next prime number, 167...

Nope. Try the next prime number, 173...

Nope. Try the next prime number, 179...

Nope. Try the next prime number, 181...

Nope. Try the next prime number, 191...

Nope. Try the next prime number, 193...

Nope. Try the next prime number, 197...

No good. 197 is larger than 193. So we're done reducing.

Congratulations! Here's your final answer to 9/100 + 7/8

9
100
+
7
8
=
193
200
© 2014 Randy Tayler