math help

What is 87/100 + 2/8?

What is 87/100 + 2/8?

Let's add

87
100
+
2
8

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

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

87/100 times 8

Now for the second term. You multiply 2 by 100, and get 200, then multiply 100 by 8 and get 800.

2/8 times 100

This gives us a new problem that looks like so:

696
800
+
200
800

Step 2

Since our denominators match, we can add the numerators.

696 + 200 = 896

So what's the answer so far?

896
800

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

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

896
800
÷ 2 =
448
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:

448
400
÷ 2 =
224
200

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:

224
200
÷ 2 =
112
100

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:

112
100
÷ 2 =
56
50

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:

56
50
÷ 2 =
28
25

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. 29 is larger than 28. So we're done reducing.

And we're done! Here's the final answer to 87/100 + 2/8

87
100
+
2
8
=
28
25
© 2014 Randy Tayler