Actually, there's nothing improper about them... It's just when the numerator is bigger then the denominator.

Like

So, let's see what this means. Let's looks at a hexagon... That's 7 pieces...

Hey, this is just !

So, must be the same as ...

Hmm... Let's see how this works!

Look at the hexagons again:

and

Hey, is a magic 1!

So,