Evaluating Exponential Expressions and Modeling Viral Spread

Miacademy & MiaPrep Learning Channel

This educational video provides a clear, step-by-step guide on how to evaluate exponential expressions containing one variable. The host, Kaylee, begins by reviewing prerequisites before diving into two distinct examples: one where the variable is the exponent ($2^x + 3$) and one where the variable is the base ($x^2 + 3x$). Through these examples, the video reinforces the three-step process of writing the expression, substituting the value, and evaluating using the order of operations. The video moves beyond abstract calculation by introducing a compelling real-world application: virology. It demonstrates how exponential expressions are used to model the spread of contagious viruses like the flu. By comparing the number of sick people on day 3 versus day 7 using the formula $p = 2^{d-1}$, the video effectively illustrates the concept of exponential growth and the speed at which it occurs. Teachers can use this video to introduce or reinforce Algebra concepts such as substitution, exponents, and order of operations. The real-world connection to science and epidemiology provides an excellent cross-curricular opportunity, helping students answer the common question, "When will I ever use this?" by showing how math helps scientists understand and predict outbreaks.