Math Club parodies the Matrix and Batman to explore the concept that subtraction is merely addition by adding the opposite. A-B=A+(-B) Does subtraction exist? Take the red gift card and find out. Addition and subtraction are two sides of the same coin and can be used to explain lots of things: elections, good and bad feelings, even retelling the plot of the Dark Knight. When the Matrix asks you to add long strings of positive and negative numbers for homework, we explain a neat little trick to help you out.