Calculating Percent of Change: Increase and Decrease

Math with Mr. J

A clear, step-by-step mathematics tutorial explaining how to calculate percent of change, covering both percent increase and percent decrease. The video introduces a consistent formula and applies it to two distinct examples: one resulting in a negative value (decrease) and one resulting in a positive value (increase). The narrator, Mr. J, emphasizes the importance of dividing by the original number to ensure accuracy. The video focuses on the specific algorithm for determining percent change: taking the difference between the new and old values, dividing that difference by the old value, and multiplying by 100 to convert the decimal to a percentage. It also clarifies how to interpret positive and negative results, explaining that a negative sign indicates a decrease while a positive sign indicates an increase. This resource is highly valuable for middle school math classrooms introducing pre-algebra concepts. It provides a reliable method for students to follow and addresses common misconceptions, such as which number to use as the denominator. Teachers can use this video to introduce the concept of percent change, as a refresher for students struggling with the steps, or as a flipped classroom assignment prior to working on real-world applications like calculating discounts or tax.