Find Unknown Side Lengths
10 min
Narrative
The purpose of this Estimation Exploration is to recall the concept of area. Students need to think strategically because the one point of reference for the size of the grassy area in the image is the car in the road. In order to facilitate mental calculation, expect students to choose multiples of 10 for the length and the width of the rectangle.
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
What is the area of one of the large rectangles in the garden?
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
- Too low: range: 2,500 sq ft or less
- About right: 2,600 to 4,800 sq ft
- Too high: 5,000 sq ft or more
Activity Synthesis (Teacher Notes)
- “What did you use in the image to make an estimate for the area of the garden?” (The car and the person gave me an idea of how big it is.)
Standards
- 5.NBT.6·Find whole-number quotients of whole numbers with up to four-digit dividends and two-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
- 5.NBT.B.6·Find whole-number quotients of whole numbers with up to four-digit dividends and two-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
15 min
20 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Find Unknown Side Lengths
10 min
Narrative
The purpose of this Estimation Exploration is to recall the concept of area. Students need to think strategically because the one point of reference for the size of the grassy area in the image is the car in the road. In order to facilitate mental calculation, expect students to choose multiples of 10 for the length and the width of the rectangle.
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
What is the area of one of the large rectangles in the garden?
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
- Too low: range: 2,500 sq ft or less
- About right: 2,600 to 4,800 sq ft
- Too high: 5,000 sq ft or more
Activity Synthesis (Teacher Notes)
- “What did you use in the image to make an estimate for the area of the garden?” (The car and the person gave me an idea of how big it is.)
Standards
- 5.NBT.6·Find whole-number quotients of whole numbers with up to four-digit dividends and two-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
- 5.NBT.B.6·Find whole-number quotients of whole numbers with up to four-digit dividends and two-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.