There are instances where the expression for the functions depends on the given interval of the input values. When this happens, we call these types of functions piecewise-defined functions. Piecewise functions are defined by different functions throughout the different intervals of the domain.
There is a clicker question built into page 2 of the flipchart that just has students review function notation and what it means to evaluate a function for a given value of x. Students will just text in their numeric answers so you can check to be sure all students understand this basic function notation before moving onto evaluating piecewise functions. In my class, we do a Homework Quiz every Monday.