math help

What is 15/60 + 5/12?

What is 15/60 + 5/12?

Let's add

15
60
+
5
12

Step 1

We have to make sure the denominators are equal.

Since 12 is evenly divided by 60, we can multiply just one term to get a common denominator.

Multiply 5 by 5, and get 25, then we multiply 12 by 5 and get 60.

5/12 times 5

So now our fractions look like this:

15
60
+
25
60

Step 2

Since our denominators match, we can add the numerators.

15 + 25 = 40

Now we have an answer.

40
60

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:

40
60
÷ 2 =
20
30

So far so good... let's try to divide by that number again.

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

20
30
÷ 2 =
10
15

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

No good. So next you try the next prime number, which is 5...

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

10
15
÷ 5 =
2
3

So far so good... let's try to divide by that number again.

No good. 5 is larger than 2. So we're done reducing.

And we're done! Here's the final answer to 15/60 + 5/12

15
60
+
5
12
=
2
3
© 2014 Randy Tayler