# Acc6.5 Proportional Relationships

In this unit, students learn to understand and use the terms “proportional,” “constant of proportionality,” and “proportional relationship,” and recognize when a relationship is or is not proportional. They represent proportional relationships with tables, equations, and graphs. Students use these terms and representations in reasoning about situations that involve constant speed, unit pricing, and measurement conversions. Then, special focus is given to circumference and area of circles as examples of proportional and nonproportional relationships, respectively. Students informally derive the formulas for circumference and area of a circle and are introduced to the value $$\pi$$.