Multiplying and dividing one-step inequalities does not seem to pose too many problems for students. That is until they encounter a problem that requires them to multiply or divide by a negative number. This is where simply teaching algorithms will mystify a student. If we teach a student that when we multiply or divide each side of an inequality by a negative number we just reverse the inequality sign and do not explain why, they become baffled by the concept. In the activity Solving and Graphing One-Step Inequalities with Multiplication and Division students will explore why an inequality sign is reversed when each side is divided or multiplied by a negative number.
Students are provided with numerous practice problems in this activity. These practice problems require students to not only solve inequalities, but also graph the solutions on a number line, and identify the inequality on a coordinate grid. If there is any truth in the saying “practice makes perfect”, this activity will prepare students for solving and graphing inequality perfection.