Perimeter Problems
10 min
Narrative
The purpose of an Estimation Exploration is to practice the skill of estimating a reasonable answer based on experience and known information.
Launch
- Groups of 2
- Display the image.
- “What is an estimate that’s too high? Too low? About right?”
- 1 minute: quiet think time
Teacher Instructions
- “Discuss your thinking with your partner.”
- 1 minute: partner discussion
- Record responses.
Student Task
The Statue of Liberty has 2 square bases—1 larger than the other. The larger base has side lengths of 132 feet each.
Estimate the perimeter of the smaller square base.
Record an estimate that is:
| too low | reasonable | too high |
|---|---|---|
Sample Response
Sample responses:
- Too low: 200–280 feet
- About right: 280–400 feet
- Too high: greater than 400 feet
Activity Synthesis (Teacher Notes)
- “If you wanted to know the perimeter of the star-shaped base, how would you find it?” (We’d need to know the length of each side and add the lengths together. If the lengths were the same, we could count them and multiply the length by the number of sides.)
- Consider asking:
- “Based on this discussion does anyone want to revise their estimate?”
Standards
- 3.MD.8·Solve real world and mathematical problems involving perimeters of polygons, including finding the perimeter given the side lengths, finding an unknown side length, and exhibiting rectangles with the same perimeter and different areas or with the same area and different perimeters.
- 3.MD.D.8·Solve real world and mathematical problems involving perimeters of polygons, including finding the perimeter given the side lengths, finding an unknown side length, and exhibiting rectangles with the same perimeter and different areas or with the same area and different perimeters.
15 min
20 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Perimeter Problems
10 min
Narrative
The purpose of an Estimation Exploration is to practice the skill of estimating a reasonable answer based on experience and known information.
Launch
- Groups of 2
- Display the image.
- “What is an estimate that’s too high? Too low? About right?”
- 1 minute: quiet think time
Teacher Instructions
- “Discuss your thinking with your partner.”
- 1 minute: partner discussion
- Record responses.
Student Task
The Statue of Liberty has 2 square bases—1 larger than the other. The larger base has side lengths of 132 feet each.
Estimate the perimeter of the smaller square base.
Record an estimate that is:
| too low | reasonable | too high |
|---|---|---|
Sample Response
Sample responses:
- Too low: 200–280 feet
- About right: 280–400 feet
- Too high: greater than 400 feet
Activity Synthesis (Teacher Notes)
- “If you wanted to know the perimeter of the star-shaped base, how would you find it?” (We’d need to know the length of each side and add the lengths together. If the lengths were the same, we could count them and multiply the length by the number of sides.)
- Consider asking:
- “Based on this discussion does anyone want to revise their estimate?”
Standards
- 3.MD.8·Solve real world and mathematical problems involving perimeters of polygons, including finding the perimeter given the side lengths, finding an unknown side length, and exhibiting rectangles with the same perimeter and different areas or with the same area and different perimeters.
- 3.MD.D.8·Solve real world and mathematical problems involving perimeters of polygons, including finding the perimeter given the side lengths, finding an unknown side length, and exhibiting rectangles with the same perimeter and different areas or with the same area and different perimeters.