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.
Student Task
9,953÷37
Record an estimate that is:
too low
about right
too high
Sample Response
Sample responses:
Too low: 100–200
About right: 200–300
Too high: 300–400
Synthesis
“How do you know 100 is too low?” (Because 100×37=3,700 and that’s much less than 9,953.)
“How can you use the value of the product 100×37 to estimate the value of 9,953÷37?” (I know that 9,953 is more than 2×3,700 but less than 3×3,700 so the quotient is more than 200 but less than 300.)
Standards
Addressing
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.