math help

What is 100/24 + 5/9?

What is 100/24 + 5/9?

Here's how you add

100
24
+
5
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 100 by 9, and get 900, then we multiply 24 by 9 and get 216.

100/24 times 9

Do the same for the second term. We multiply 5 by 24, and get 120, then multiply 24 by 9 and get 216.

5/9 times 24

The problem now has new fractions to add:

900
216
+
120
216

Step 2

Since our denominators match, we can add the numerators.

900 + 120 = 1020

This yields the answer

1020
216

Step 3

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

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:

1020
216
÷ 2 =
510
108

Let's try dividing by that again...

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

510
108
÷ 2 =
255
54

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:

255
54
÷ 3 =
85
18

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...

No good. 19 is larger than 18. So we're done reducing.

There you have it! Here's the final answer to 100/24 + 5/9

100
24
+
5
9
=
85
18
© 2014 Randy Tayler