What is a fraction?

0:00A fraction is just a way of describing part of a whole. If you cut a roti into four equal pieces and take one, you've taken one quarter — written one over four.

0:24The bottom number, the denominator, tells you how many equal pieces the whole was cut into. The top number, the numerator, tells you how many of those pieces you have.

0:51Here's the part people miss: the pieces have to be equal. Three big slices and one tiny sliver isn't quarters. Equal pieces is the whole idea.