How to Calculate and Understand Percent Error

Math with Mr. J

This instructional math video introduces students to the concept of percent error, a critical statistical tool used to determine the accuracy of an estimate or measurement relative to an actual value. The narrator, Mr. J, clearly defines percent error and breaks down the formula step-by-step, including calculating the difference, taking the absolute value, dividing by the actual value, and converting the resulting decimal to a percentage. The video explores key themes such as the difference between absolute error (raw numbers) and relative error (percentages). Through four distinct examples, the video demonstrates how a small absolute error can result in a large percent error when dealing with small numbers, while a large absolute error might result in a tiny percent error when dealing with massive numbers. This helps students understand why context and magnitude matter in data analysis. This resource is highly valuable for middle and high school math classrooms as it moves beyond simple calculation into statistical reasoning. Teachers can use this video to bridge the gap between simple arithmetic and data interpretation. It serves as an excellent primer for science labs where experimental error is calculated, or for math units dealing with ratios, proportions, and real-world estimation.