Lesson 18
Two Truths and a Lie (optional)
Lesson Purpose
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
- Let’s compare facts about animals.
Required Materials
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
Suggested Centers
- Can You Draw It? (1–5), Stage 4: Area and Perimeter (Supporting)
- Rectangle Rumble (3–5), Stage 3: Factors 1–10 (Supporting)