Having trouble explaining why an inequality sign changes when you divide or multiply by a negative number? This PowerPoint presentation helps students make sense of this abstract rule. The PowerPoint begins with the inequality 8<10 and shows, using number lines and animations, how the inequality remains true as various computations are applied to each side. It then uses number lines and animation to show how multiplication and division by negatives causes the inequality to no longer be true, thus motivating the need to change the inequality sign. It also includes many solving examples to clearly illustrate when we must change the inequality sign and when we leave it alone. This item can be edited and has been very popular with middle and high school teachers in my district.