math help

What is 28/100 + 4/9?

What is 28/100 + 4/9?

Let's add

28
100
+
4
9

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 9, and get 252, then we multiply 100 by 9 and get 900.

28/100 times 9

Now for the second term. You multiply 4 by 100, and get 400, then multiply 100 by 9 and get 900.

4/9 times 100

This gives us a new problem that looks like so:

252
900
+
400
900

Step 2

Since our denominators match, we can add the numerators.

252 + 400 = 652

So what's the answer so far?

652
900

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:

652
900
÷ 2 =
326
450

Let's try dividing by that again...

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

326
450
÷ 2 =
163
225

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...

No good. 167 is larger than 163. So we're done reducing.

There you have it! Here's the final answer to 28/100 + 4/9

28
100
+
4
9
=
163
225
© 2014 Randy Tayler