In this lesson, students are given limited information about coordinate pairs on the graph of an exponential function and asked to write the function algebraically. Students should look for connections between equations of the form , the -intercept, and the growth factor.

An optional activity offers another chance for students to practice rewriting exponential expressions to highlight different aspects of the exponential growth, such as the growth factor or the amount of time it takes to double.

To calculate the growth factor from coordinate pairs, students must make use of the structure of exponential growth over equal intervals (MP7). Students must make sense of the problems and persist in solving them to write the equations using the Information Gap routine (MP1). Precise language is also important to obtain useful information as part of that routine (MP6).