Compare and Order Decimals
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. In this case, the given decimal pushes students to think in terms of increments of tenths (0.1) and to relate the fractional measurement to nearby whole numbers.
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 person in the image is 1.7 meters tall.
Estimate the wingspan of the eagle in meters.
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
Sample responses:
- Too low: 0–1.9
- About right: 2.0–2.5
- Too high: 2.6–3.0
Activity Synthesis (Teacher Notes)
- “Why might 1.8 meters be too low of an estimate?”
- “Where might a height of 1 meter be on the image of the person? On the image of the eagle?”
- Consider asking:
- “Is anyone’s estimate less than 2? Is anyone’s estimate greater than 3?”
- “Based on this discussion does anyone want to revise their estimate?”
Standards
- 4.NF.7·Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols >, =, or < , and justify the conclusions, e.g., by using the number line or another visual model.
- 4.NF.C.7·Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols <span class="math">\(>\)</span>, =, or <span class="math">\(<\)</span>, and justify the conclusions, e.g., by using a visual model.
15 min
20 min
Knowledge Components
All skills for this lesson
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Compare and Order Decimals
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. In this case, the given decimal pushes students to think in terms of increments of tenths (0.1) and to relate the fractional measurement to nearby whole numbers.
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 person in the image is 1.7 meters tall.
Estimate the wingspan of the eagle in meters.
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
Sample responses:
- Too low: 0–1.9
- About right: 2.0–2.5
- Too high: 2.6–3.0
Activity Synthesis (Teacher Notes)
- “Why might 1.8 meters be too low of an estimate?”
- “Where might a height of 1 meter be on the image of the person? On the image of the eagle?”
- Consider asking:
- “Is anyone’s estimate less than 2? Is anyone’s estimate greater than 3?”
- “Based on this discussion does anyone want to revise their estimate?”
Standards
- 4.NF.7·Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols >, =, or < , and justify the conclusions, e.g., by using the number line or another visual model.
- 4.NF.C.7·Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols <span class="math">\(>\)</span>, =, or <span class="math">\(<\)</span>, and justify the conclusions, e.g., by using a visual model.