# What is 1/4 - 4/8?

Here's how to subtract 4/8 from 1/4:

 1 4
 4 8

## Step 1

We can't subtract two fractions with different denominators. So you need to get a common denominator. 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 1 by 8, and get 8.

Then we multiply 4 by 4, and get 16.

Next we give both terms new denominators -- 4 × 8 = 32.

So now our fractions look like this:

 8 32
 16 32

## Step 2

Since our denominators match, we can subtract the numerators.

8 − 16 = -8

 -8 32

## 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:

 -8 32
÷ 2 =
 -4 16

Let's try dividing by 2 again...

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

 -4 16
÷ 2 =
 -2 8

Let's try dividing by 2 again...

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

 -2 8
÷ 2 =
 -1 4

Let's try dividing by 2 again...

No good. 2 is larger than -1. So we're done reducing.

There you have it! The final answer is:
 1 4
 4 8
=
 1 4