More Division

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.

Student Task

9,953÷379,953\div37

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
Activity Synthesis (Teacher Notes)
  • “How do you know 100 is too low?” (Because 100×37=3,700100\times37=3,700 and that’s much less than 9,953.)
  • “How can you use the value of the product 100×37100 \times 37 to estimate the value of 9,953÷379,953 \div 37?” (I know that 9,953 is more than 2×3,7002 \times 3,700 but less than 3×3,7003 \times 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.

20 min

15 min