In this video, we learn how to use the PRIME operator in math. The prime operator is the opposite of something in the equation. Take a look at the illustration in the video that is shown. Once you see that, you will be able to tell what A prime and B prime are. A prime is the opposite of "A". If a number is shaded in "A" it should not be shaded in "A Prime". The same goes for the prime of the letter "B". Just pay attention to what the numbers selected for each letter is, then use the opposite to find the prime!