# Lesson 23

Modeling Constraints

These materials, when encountered before Algebra 1, Unit 2, Lesson 23 support success in that lesson.

### Lesson Narrative

The mathematical purpose of this lesson is to introduce students to the banking and insurance contexts they will work with in their Algebra 1 lesson, and to demonstrate a specific strategy for modeling situations using inequalities.

Students who struggle sometimes have a hard time making sense of a context and representing it symbolically, even when they could successfully think of specific values that will satisfy the situation, or test whether specific values will work. This strategy supports them to use their quantitative reasoning and generalize it to create a symbolic description of the inequality (MP2), by taking advantage of repeated reasoning (MP8).

### Learning Goals

Teacher Facing

• Write inequalities that describe constraints on two-variable situations.

### Student Facing

• Let’s represent some situations from banking and insurance.