The purpose of an Estimation Exploration is for students to practice the skill of estimating a reasonable answer based on experience and known information. It gives students a low-stakes opportunity to share a mathematical claim and the thinking behind it (MP3).
Launch
Groups of 2
Display the expression.
“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.
Monitor for students who estimate by using 10,000×900.
Student Task
9,999 ×896
Record an estimate that is:
too low
about right
too high
Sample Response
Sample responses:
too low: 7,000,000–8,000,000
about right: 8,000,000–10,000,000
too high: 10,000,000–11,000,000
Activity Synthesis (Teacher Notes)
Invite students to share estimates.
“Why is 10,000×900 a good estimate for the product?” (10,000 is just 1 more than 9,999 and 896 is close to 900.)
“What is the value of 10,000×900? How do you know?” (9,000,000, because the two numbers have 6 factors of 10 combined.)
Standards
Addressing
5.NBT.5·Fluently multiply multi-digit whole numbers using the standard algorithm.
5.NBT.B.5·Fluently multiply multi-digit whole numbers using the standard algorithm.
20 min
15 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
More Multiplication
10 min
Narrative
The purpose of an Estimation Exploration is for students to practice the skill of estimating a reasonable answer based on experience and known information. It gives students a low-stakes opportunity to share a mathematical claim and the thinking behind it (MP3).
Launch
Groups of 2
Display the expression.
“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.
Monitor for students who estimate by using 10,000×900.
Student Task
9,999 ×896
Record an estimate that is:
too low
about right
too high
Sample Response
Sample responses:
too low: 7,000,000–8,000,000
about right: 8,000,000–10,000,000
too high: 10,000,000–11,000,000
Activity Synthesis (Teacher Notes)
Invite students to share estimates.
“Why is 10,000×900 a good estimate for the product?” (10,000 is just 1 more than 9,999 and 896 is close to 900.)
“What is the value of 10,000×900? How do you know?” (9,000,000, because the two numbers have 6 factors of 10 combined.)
Standards
Addressing
5.NBT.5·Fluently multiply multi-digit whole numbers using the standard algorithm.
5.NBT.B.5·Fluently multiply multi-digit whole numbers using the standard algorithm.