Learning goals: Teacher Facing Interpret a graph of a piecewise function or the rules given in function notation, and explain the rules (orally and in writing) in terms of a situation. Sketch a graph that represents the rules of a piecewise function, paying special attention to the endpoints of each interval. Understand a piecewise function as a function defined by different rules for different intervals of the domain. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from Alg1.4 Functions, Algebra 1.