Supply and Demand

Grade Levels

10th Grade, 11th Grade, 12th Grade, 9th Grade

Course, Subject

Economics

Related Academic Standards

CC.2.1.8.C.1 CC.2.1.8.C.1

Intentionally Blank

CC.2.2.7.B.3 CC.2.2.7.B.3

Model and solve real-world and mathematical problems by using and connecting numerical, algebraic, and/or graphical representations.

CC.2.2.8.B.3 CC.2.2.8.B.3

Analyze and solve linear equations and pairs of simultaneous linear equations.

6.2.9.D 6.2.9.D

Explain the laws of supply and demand and how these affect the prices of goods and services.

M07.B-E.2.1.1 M07.B-E.2.1.1

Apply properties of operations to calculate with numbers in any form; convert between forms as appropriate. Example: If a woman making $25 an hour gets a 10% raise, she will make an additional 1/10 of her salary an hour, or $2.50, for a new salary of $27.50 an hour (or 1.1 × $25 = $27.50).

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Big Ideas

Mathematical functions are relationships that assign each member of one set (domain) to a unique member of another set (range), and the relationship is recognizable across representations.

Numbers, measures, expressions, equations, and inequalities can represent mathematical situations and structures in many equivalent forms.

Patterns exhibit relationships that can be extended, described, and generalized.

Relations and functions are mathematical relationships that can be represented and analyzed using words, tables, graphs, and equations.

Similarity relationships between objects are a form of proportional relationships. Congruence describes a special similarity relationship between objects and is a form of equivalence.

The set of real numbers has infinite subsets including the sets of whole numbers, integers, rational, and irrational numbers.

There are some mathematical relationships that are always true and these relationships are used as the rules of arithmetic and algebra and are useful for writing equivalent forms of expressions and solving equations and inequalities.

Two variable quantities are proportional if their values are in a constant ratio. The relationship between proportional quantities can be represented as a linear function.
Concepts

Graphing on a coordinate plane

Linear equations and inequalities

Linear functions

Rate of change
Competencies

Apply a variety of strategies for proportional reasoning and use them to solve real world problems, including problems dealing with similarity and rates of change.

Use linear functions, linear equations, and linear inequalities to represent, analyze, and solve a variety of problems.

Description

In this grades 9–12 activity, students write and solve a system of linear equations in a real-world setting. Students should be familiar with finding linear equations from 2 points or from the slope andy-intercept. Graphing calculators are not necessary for this activity, but could be used to extend the ideas found on the second activity sheet. Parts of this lesson plan were adapted from the October 1991 edition of Mathematics Teacher.

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