7.RP.2b: Understanding the Constant of Proportionality in Various Proportional Relationships

Grade: 7th Grade

Domain: RP: Ratios and Proportional Relationships

Standard Description

Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships.

Domain Description

Compute the rates associated with ratios of fractions, like lengths and areas. For instance, for a person walking 1/2 mile every 1/4 hour, the rate would be denoted as 1/2/1/4 miles per hour, or 2 miles per hour.

Determine if two quantities share a proportional relationship by observing if the graph of their ratios is a straight line through the origin. Recognize the constant of proportionality in different formats such as tables, diagrams, and verbal descriptions.

Create equations to represent proportional relationships. As an example; if the total cost is proportional to the number of items bought at a rate p, the equation becomes t = pn.

Interpret what a point (x, y) on a graph of a proportional relationship means considering points like (0, 0) and (1, r), where r represents the unit rate.

Employ proportional relationships to tackle multistep ratio and percent calculations, such as simple interest, taxes, markups and markdowns, commissions, fees, and percent variations.