math help

What is 87/100 + 5/8?

What is 87/100 + 5/8?

Here's how we add

87
100
+
5
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 87 by 8, and get 696, then we multiply 100 by 8 and get 800.

87/100 times 8

Do the same for the second term. We multiply 5 by 100, and get 500, then multiply 100 by 8 and get 800.

5/8 times 100

So now our fractions look like this:

696
800
+
500
800

Step 2

Since our denominators match, we can add the numerators.

696 + 500 = 1196

So the answer is:

1196
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:

1196
800
÷ 2 =
598
400

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

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

598
400
÷ 2 =
299
200

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...

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. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. So next you try the next prime number, which is 61...

No good. So next you try the next prime number, which is 67...

No good. So next you try the next prime number, which is 71...

No good. So next you try the next prime number, which is 73...

No good. So next you try the next prime number, which is 79...

No good. So next you try the next prime number, which is 83...

No good. So next you try the next prime number, which is 89...

No good. So next you try the next prime number, which is 97...

No good. So next you try the next prime number, which is 101...

No good. So next you try the next prime number, which is 103...

No good. So next you try the next prime number, which is 107...

No good. So next you try the next prime number, which is 109...

No good. So next you try the next prime number, which is 113...

No good. So next you try the next prime number, which is 127...

No good. So next you try the next prime number, which is 131...

No good. So next you try the next prime number, which is 137...

No good. So next you try the next prime number, which is 139...

No good. So next you try the next prime number, which is 149...

No good. So next you try the next prime number, which is 151...

No good. So next you try the next prime number, which is 157...

No good. So next you try the next prime number, which is 163...

No good. So next you try the next prime number, which is 167...

No good. So next you try the next prime number, which is 173...

No good. So next you try the next prime number, which is 179...

No good. So next you try the next prime number, which is 181...

No good. So next you try the next prime number, which is 191...

No good. So next you try the next prime number, which is 193...

No good. So next you try the next prime number, which is 197...

No good. So next you try the next prime number, which is 199...

No good. So next you try the next prime number, which is 211...

No good. 211 is larger than 200. So we're done reducing.

And we're done! Here's the final answer to 87/100 + 5/8

87
100
+
5
8
=
299
200
© 2014 Randy Tayler