 What is 1/2 - 4/12? Here's how to subtract 4/12 from 1/2:

 1 2
 4 12

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 12, and get 12.

Then we multiply 4 by 2, and get 8.

Next we give both terms new denominators -- 2 × 12 = 24.

So now our fractions look like this:

 12 24
 8 24

Step 2

Since our denominators match, we can subtract the numerators.

12 − 8 = 4

 4 24

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:

 4 24
÷ 2 =
 2 12

Let's try dividing by 2 again...

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

 2 12
÷ 2 =
 1 6

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 2
 4 12
=
 1 6