math help

What is 15/60 + 1/8?

What is 15/60 + 1/8?

Here's how to add

15
60
+
1
8

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 15 by 8, and get 120, then we multiply 60 by 8 and get 480.

15/60 times 8

Do the same for the second term. We multiply 1 by 60, and get 60, then multiply 60 by 8 and get 480.

1/8 times 60

So now our fractions look like this:

120
480
+
60
480

Step 2

Since our denominators match, we can add the numerators.

120 + 60 = 180

Now we have an answer.

180
480

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:

180
480
÷ 2 =
90
240

Let's try dividing by that again...

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

90
240
÷ 2 =
45
120

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:

45
120
÷ 3 =
15
40

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 5...

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

15
40
÷ 5 =
3
8

Let's try dividing by that again...

No good. 5 is larger than 3. So we're done reducing.

There you have it! Here's the final answer to 15/60 + 1/8

15
60
+
1
8
=
3
8
© 2014 Randy Tayler