math help

What is 5/100 + 3/9?

What is 5/100 + 3/9?

Here's how you add

5
100
+
3
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 5 by 9, and get 45, then we multiply 100 by 9 and get 900.

5/100 times 9

Now for the second term. You multiply 3 by 100, and get 300, then multiply 100 by 9 and get 900.

3/9 times 100

This gives us a new problem that looks like so:

45
900
+
300
900

Step 2

Since our denominators match, we can add the numerators.

45 + 300 = 345

So what's the answer so far?

345
900

Step 3

Can this fraction be reduced?

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

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

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

345
900
÷ 3 =
115
300

Let's try dividing by that again...

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

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

115
300
÷ 5 =
23
60

Let's try dividing by that again...

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...

No good. 29 is larger than 23. So we're done reducing.

There you have it! Here's the final answer to 5/100 + 3/9

5
100
+
3
9
=
23
60
© 2014 Randy Tayler