# Lesson 19

Situations and Equations

### Lesson Purpose

The purpose of this lesson is for students to represent and solve two-step word problems.

### Lesson Narrative

In this lesson, students are able to apply what they have learned in this section to write equations that represent two-step word problems using a letter for the unknown quantity. They persevere to solve two-step word problems, and decide if their answer makes sense (MP1).

• Engagement
• MLR5

### Learning Goals

Teacher Facing

• Represent and solve two-step word problems using equations with a letter standing for the unknown quantity.

### Student Facing

• Let’s represent and solve problems.

### Lesson Timeline

 Warm-up 10 min Activity 1 20 min Activity 2 15 min Lesson Synthesis 10 min Cool-down 5 min

### Teacher Reflection Questions

Who has been sharing their ideas in class lately? Make a note of students whose ideas have not been featured in class and look for an opportunity for them to share their thinking in tomorrow’s lesson.

### Suggested Centers

• Tic Tac Round (3–5), Stage 1: Nearest Ten or Hundred (Addressing)
• Number Puzzles: Addition and Subtraction (1–4), Stage 5: Within 1,000 (Addressing)
• Five in a Row: Multiplication (3–5), Stage 2: Factors 1–9 (Supporting)