math help

What is 24/12 + 3/9?

What is 24/12 + 3/9?

This is how to add

24
12
+
3
9

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 24 by 9, and get 216, then we multiply 12 by 9 and get 108.

24/12 times 9

Do the same for the second term. We multiply 3 by 12, and get 36, then multiply 12 by 9 and get 108.

3/9 times 12

So now our fractions look like this:

216
108
+
36
108

Step 2

Since our denominators match, we can add the numerators.

216 + 36 = 252

So the answer is:

252
108

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:

252
108
÷ 2 =
126
54

Let's try dividing by that again...

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

126
54
÷ 2 =
63
27

Let's try dividing by that again...

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:

63
27
÷ 3 =
21
9

Let's try dividing by that again...

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

21
9
÷ 3 =
7
3

Let's try dividing by that again...

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

No good. 5 is larger than 3. So we're done reducing.

There you have it! Here's the final answer to 24/12 + 3/9

24
12
+
3
9
=
7
3
© 2014 Randy Tayler