Harry has 1/4 of apple pie that he wants to cut into 3 equal slices. what fraction of the whole pie is each slice?

1/12

Explanation:
1/4 : 3 = (You have to divide by three, because you cut your part into 3 equal slices)
1/4 : 3/1 = 
1/4 x 1/3 = (When dividing by a fraction, you have to multiply by its opposite)
1/12 (Hence, the answer is 1/12)

Good morning. Let's figure this out.
I'm calling Harry, "Hairy" because it sounds better.

So, my friend Hairy here, has 1/4 of an apple pie.  Hairy wants to split 1/4 into 3. What would this call for? Division. Observe.

(We all know 3/1 = 3)

But wait, what must we do when we divide fractions? We must flip one fraction and multiply across. So instead the fraction would look a little like this: 



And that, is the answer. The fractions of each slice of Hairy's pie would be:

You're welcome.