Learning goals: Teacher Facing Compare, contrast, and critique (orally and in writing) different ways to express the constant of proportionality for a relationship. Explain (orally) how to determine the constant of proportionality for a proportional relationship represented in a table. Interpret the constant of proportionality for a relationship in the context of constant speed. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 7.2 Introducing Proportional Relationships, Grade 7.