Round Decimals
10 min
Narrative
The purpose of this Estimation Exploration is for students to use their experience with the number line, decimals, and fractions to estimate the value of a number located on the number line. Students may answer with a fraction but are likely to write a decimal since they have been working with decimals for the last several lessons. In the Activity Synthesis, students reflect on how having tick marks for each tenth would help improve their estimate.
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 number might be represented on the point on the number line?
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
Sample responses:
- too low: 0.1 to 0.2
- about right: 0.2 to 0.4
- too high: 0.4 to 1
Activity Synthesis (Teacher Notes)
- “Would having tick marks for each tenth on the number line help improve your estimate? Why or why not?” (Yes, because I could see if it is one of the tenths and if not, where it is relative to those numbers.)
Standards
- 5.NBT.3.b·Compare two decimals to thousandths based on meanings of the digits in each place, using >, =, and < symbols to record the results of comparisons.
- 5.NBT.A.3.b·Compare two decimals to thousandths based on meanings of the digits in each place, using <span class="math">\(>\)</span>, =, and <span class="math">\(<\)</span> symbols to record the results of comparisons.
15 min
15 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Round Decimals
10 min
Narrative
The purpose of this Estimation Exploration is for students to use their experience with the number line, decimals, and fractions to estimate the value of a number located on the number line. Students may answer with a fraction but are likely to write a decimal since they have been working with decimals for the last several lessons. In the Activity Synthesis, students reflect on how having tick marks for each tenth would help improve their estimate.
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 number might be represented on the point on the number line?
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
Sample responses:
- too low: 0.1 to 0.2
- about right: 0.2 to 0.4
- too high: 0.4 to 1
Activity Synthesis (Teacher Notes)
- “Would having tick marks for each tenth on the number line help improve your estimate? Why or why not?” (Yes, because I could see if it is one of the tenths and if not, where it is relative to those numbers.)
Standards
- 5.NBT.3.b·Compare two decimals to thousandths based on meanings of the digits in each place, using >, =, and < symbols to record the results of comparisons.
- 5.NBT.A.3.b·Compare two decimals to thousandths based on meanings of the digits in each place, using <span class="math">\(>\)</span>, =, and <span class="math">\(<\)</span> symbols to record the results of comparisons.