# Lesson 18

Dos verdades y una mentira (optional)

### Lesson Purpose

The purpose of this lesson is for students to apply their understanding of multiplication and measurement conversion to compare facts about animals.

### Lesson Narrative

This lesson is optional because it does not address any new mathematical content standards. This lesson does provide students with an opportunity to apply precursor skills of mathematical modeling. In this lesson, students write true and false statements involving multiplicative comparisons and unit conversions. They have an opportunity to choose the animals to compare and which facts to use.

Then, students determine which of their classmates’ statements are true and which are false. At the end of this activity, they have an opportunity to revise their earlier statements to make them clearer or stronger. As students discuss and justify their decisions, they share a mathematical claim and the thinking behind it (MP3).

• Representation
• MLR2

### Learning Goals

Teacher Facing

• Analyze, describe, and represent multiplicative comparison situations.
• Convert from larger units to smaller units within a given system of measurement.
• Solve problems involving multiplicative comparison and measurement.

### Student Facing

• Comparemos hechos sobre animales.

### Required Materials

Materials to Gather

Materials to Copy

### Required Preparation

Activity 1:

• If students are performing their own research, provide access to books about animals or Internet-enabled devices.

### Lesson Timeline

 Warm-up 10 min Activity 1 20 min Activity 2 20 min Lesson Synthesis 10 min

### Teacher Reflection Questions

What aspects of today’s lesson allowed each of your students to see themselves as capable and competent in reasoning mathematically?

### Suggested Centers

• Can You Draw It? (1–5), Stage 4: Area and Perimeter (Supporting)
• Rectangle Rumble (3–5), Stage 3: Factors 1–10 (Supporting)