math help

What is 15/60 + 1/9?

What is 15/60 + 1/9?

Let's add

15
60
+
1
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 15 by 9, and get 135, then we multiply 60 by 9 and get 540.

15/60 times 9

Now for the second term. You multiply 1 by 60, and get 60, then multiply 60 by 9 and get 540.

1/9 times 60

This gives us a new problem that looks like so:

135
540
+
60
540

Step 2

Since our denominators match, we can add the numerators.

135 + 60 = 195

So what's the answer so far?

195
540

Step 3

Can this fraction be reduced?

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

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

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

195
540
÷ 3 =
65
180

Now, try the same number again.

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

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

65
180
÷ 5 =
13
36

Now, try the same number again.

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...

No good. 17 is larger than 13. So we're done reducing.

Congratulations! Here's your final answer to 15/60 + 1/9

15
60
+
1
9
=
13
36
© 2014 Randy Tayler