Lesson 16

Representing Contexts with Equations

Lesson Narrative

In the previous lesson students looked at methods for solving equations with rational numbers. In this lesson students choose equations that represent a context, and write their own equations given a context. Students are also encouraged to look at the structure of an equation and decide if its solution is positive or negative, without solving it (MP7).

Learning Goals

Teacher Facing

  • Coordinate (orally and in writing) verbal descriptions, equations, and diagrams that represent the same situation involving an unknown amount in the context of temperature or elevation.
  • Write equations of the form $x+p=q$ or $px=q$ to represent and solve a problem in an unfamiliar context, and present the solution method (using words and other representations).

Student Facing

Let’s write equations that represent situations.

Learning Targets

Student Facing

  • I can explain what the solution to an equation means for the situation.
  • I can write and solve equations to represent situations that involve rational numbers.

CCSS Standards

Building On

Addressing

Building Towards

Glossary Entries

  • variable

    A variable is a letter that represents a number. You can choose different numbers for the value of the variable.

    For example, in the expression \(10-x\), the variable is \(x\). If the value of \(x\) is 3, then \(10-x=7\), because \(10-3=7\). If the value of \(x\) is 6, then \(10-x=4\), because \(10-6=4\).