The video teaches the viewer to divide one fraction by another. The process involves taking the reciprocal of the second fraction (flipping it upside down); so if you want to divide 7/3 by 1/2, you flip 1/2: it becomes 2/1. Then it is a multiplication problem: 7/3 x 2/1. The way to multiply two fractions is to multiply the top numbers (here, 7 x 2) over the bottom numbers (here, 3 x 1). So the product of 7/3 x 2/1 is 14/3.