math help

What is 9/60 + 5/8?

What is 9/60 + 5/8?

Here's how you add

9
60
+
5
8

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 9 by 8, and get 72, then we multiply 60 by 8 and get 480.

9/60 times 8

Do the same for the second term. We multiply 5 by 60, and get 300, then multiply 60 by 8 and get 480.

5/8 times 60

The problem now has new fractions to add:

72
480
+
300
480

Step 2

Since our denominators match, we can add the numerators.

72 + 300 = 372

This yields the answer

372
480

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:

372
480
÷ 2 =
186
240

Now, try the same number again.

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

186
240
÷ 2 =
93
120

Now, try the same number again.

Nope. Try the next prime number, 3...

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

93
120
÷ 3 =
31
40

Now, try the same number again.

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

No good. 37 is larger than 31. So we're done reducing.

Congratulations! Here's your final answer to 9/60 + 5/8

9
60
+
5
8
=
31
40
© 2014 Randy Tayler