math help

What is 3/24 + 6/9?

What is 3/24 + 6/9?

Here's how to add

3
24
+
6
9

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 3 by 9, and get 27, then we multiply 24 by 9 and get 216.

3/24 times 9

Do the same for the second term. We multiply 6 by 24, and get 144, then multiply 24 by 9 and get 216.

6/9 times 24

The problem now has new fractions to add:

27
216
+
144
216

Step 2

Since our denominators match, we can add the numerators.

27 + 144 = 171

This yields the answer

171
216

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing 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:

171
216
÷ 3 =
57
72

Let's try dividing by that again...

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

57
72
÷ 3 =
19
24

Let's try dividing by that again...

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...

No good. 23 is larger than 19. So we're done reducing.

There you have it! Here's the final answer to 3/24 + 6/9

3
24
+
6
9
=
19
24
© 2014 Randy Tayler