How to Calculate Percent Increase and Decrease

mathantics

This educational video from Math Antics provides a clear and comprehensive guide to calculating percent change, covering both percent increase and percent decrease. Host Rob simplifies the transition from absolute change (actual value difference) to relative change (percentage), using visual models and equivalent fractions to build conceptual understanding before introducing the standard formula. The video addresses real-world scenarios like sales discounts, population growth, and business metrics to demonstrate practical applications. Key themes include the relationship between fractions and percentages, the importance of order in subtraction to determine positive (increase) or negative (decrease) values, and the concept of equivalent fractions. The video also explores special cases that often confuse students, such as why doubling an amount is a 100% increase while halving it is only a 50% decrease, and how percent increases can exceed 100%. For educators, this resource is invaluable for bridging the gap between basic percentage skills and algebraic application. The dual approach of showing visual bar models alongside the algebraic method `(Change / Original) * 100` helps differentiate instruction for visual learners and abstract thinkers. The built-in "intuition checks" encourage students to validate their answers logically rather than blindly following algorithms.