Evaluating Algebraic Expressions: A Step-by-Step Guide

The Organic Chemistry Tutor

This instructional video provides a comprehensive tutorial on evaluating algebraic expressions through substitution. The narrator guides viewers through a progressive series of examples, starting with simple linear expressions and advancing to more complex problems involving exponents, parentheses, multiple variables, and rational expressions. The video emphasizes the importance of following the Order of Operations (PEMDAS) to ensure accuracy when simplifying expressions after substitution. Key themes include variable substitution, integer arithmetic (operations with positive and negative numbers), and the hierarchy of mathematical operations. The video specifically addresses common student errors, such as performing subtraction before multiplication or applying exponents incorrectly. It concludes with a practical application problem involving a physics formula for projectile motion, demonstrating how these algebraic skills apply to real-world scenarios. For educators, this video serves as an excellent direct instruction tool or review resource for Pre-Algebra and Algebra 1 students. It allows for a "pause-and-practice" teaching model where students can attempt each problem before watching the solution. The clear, step-by-step breakdown makes it particularly useful for scaffolding learning, helping students transition from basic substitution to evaluating complex formulas involving motion and gravity.