math help

What is 28/100 + 5/8?

What is 28/100 + 5/8?

Let's add

28
100
+
5
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 28 by 8, and get 224, then we multiply 100 by 8 and get 800.

28/100 times 8

Now for the second term. You multiply 5 by 100, and get 500, then multiply 100 by 8 and get 800.

5/8 times 100

This gives us a new problem that looks like so:

224
800
+
500
800

Step 2

Since our denominators match, we can add the numerators.

224 + 500 = 724

So what's the answer so far?

724
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:

724
800
÷ 2 =
362
400

Let's try dividing by that again...

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

362
400
÷ 2 =
181
200

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

Nope! So now we try the next greatest prime number, 53...

Nope! So now we try the next greatest prime number, 59...

Nope! So now we try the next greatest prime number, 61...

Nope! So now we try the next greatest prime number, 67...

Nope! So now we try the next greatest prime number, 71...

Nope! So now we try the next greatest prime number, 73...

Nope! So now we try the next greatest prime number, 79...

Nope! So now we try the next greatest prime number, 83...

Nope! So now we try the next greatest prime number, 89...

Nope! So now we try the next greatest prime number, 97...

Nope! So now we try the next greatest prime number, 101...

Nope! So now we try the next greatest prime number, 103...

Nope! So now we try the next greatest prime number, 107...

Nope! So now we try the next greatest prime number, 109...

Nope! So now we try the next greatest prime number, 113...

Nope! So now we try the next greatest prime number, 127...

Nope! So now we try the next greatest prime number, 131...

Nope! So now we try the next greatest prime number, 137...

Nope! So now we try the next greatest prime number, 139...

Nope! So now we try the next greatest prime number, 149...

Nope! So now we try the next greatest prime number, 151...

Nope! So now we try the next greatest prime number, 157...

Nope! So now we try the next greatest prime number, 163...

Nope! So now we try the next greatest prime number, 167...

Nope! So now we try the next greatest prime number, 173...

Nope! So now we try the next greatest prime number, 179...

Nope! So now we try the next greatest prime number, 181...

Nope! So now we try the next greatest prime number, 191...

No good. 191 is larger than 181. So we're done reducing.

There you have it! Here's the final answer to 28/100 + 5/8

28
100
+
5
8
=
181
200
© 2014 Randy Tayler