Curriculum  /  Math  /  5th Grade  /  Unit 2: Multiplication and Division of Whole Numbers  /  Lesson 15

Multiplication and Division of Whole Numbers

Lesson 15

Math

Unit 2

5th Grade

Lesson 15 of 20

Objective

Divide two-digit dividends by two-digit divisors with one-digit quotients and remainders in the ones place.

Common Core Standards

Core Standards

  • 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.

Foundational Standards

  • 4.NBT.B.4
  • 4.NBT.B.6
  • 5.NBT.A.1
  • 5.NBT.A.2

Criteria for Success

  1. Estimate quotients of two-digit dividends and two-digit divisors with one-digit quotients.
  2. Use the estimate to approximate each value in the quotient.
  3. Adjust an estimate when the estimate would yield too large a result. 
  4. Divide two-digit dividends by two-digit divisors with one-digit quotients and remainders in the ones place.
  5. Assess the reasonableness of an answer using estimation and/or the relationship between multiplication and division to check answers (MP.1).
  6. Solve word problems involving division, including those that require the interpretation of the remainder (MP.1, MP.4).

Tips for Teachers

In Lesson 15, students first encounter a case that requires the need to adjust an estimate, since it is the first time they are estimating not just the dividend but also the divisor and using that estimate to compute. As noted in the Progressions, “even if students round the dividend appropriately, the resulting estimate may need to be adjusted up or down. Sometimes multiplying the ones of a two-digit divisor composes a new thousand, hundred, or ten. These newly composed units can be written as part of the division computation, added mentally, or as part of a separate multiplication computation” (NBT Progression, p. 18).

Fishtank Plus

Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.

Anchor Tasks

25-30 minutes

Problem 1

Estimate the following quotient. Then compute it.

$$82\div27$$

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 2

Reto is trying to solve $$84\div23$$. He estimates the quotient to be $$84\div23 \approx 80 \div 20 = 4$$. He starts to compute below:

a.   What do you notice about Reto’s work so far? What do you wonder?

b.   Based on what you noticed and wondered about Reto’s work, find the solution to $$84\div23$$.

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

References

EngageNY Mathematics Grade 5 Mathematics > Module 2 > Topic F > Lesson 20 — Concept Development

Grade 5 Mathematics > Module 2 > Topic F > Lesson 20 of the New York State Common Core Mathematics Curriculum from EngageNY and Great Minds. © 2015 Great Minds. Licensed by EngageNY of the New York State Education Department under the CC BY-NC-SA 3.0 US license. Accessed Dec. 2, 2016, 5:15 p.m..

Modified by Fishtank Learning, Inc.

Problem 3

A ferry can hold 19 cars. How many trips will it have to make to carry 83 cars across the lake?

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem Set

15-20 minutes

Discussion of Problem Set

  • Did your initial estimates work for every example in #1? Why or why not? 
  • In #2, what would you tell Linda in order to help her solve the problem? What lesson does Linda need to learn? What is another way that Linda could have estimated that would have eliminated the issue she encountered in the standard algorithm?
  • Explain your thought process as you set up and began to solve #3 and #4. What was challenging or unique about them? 
  • Talk about the importance of estimation when dividing with two-digit divisors.

Target Task

5-10 minutes

Problem 1

Solve. 

$${87\div31}$$

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 2

Sam played arcade games and won 79 tickets. You can buy 1 prize for every 18 tickets earned. Sam bought as many prizes as he could with his tickets. How many prizes was Sam able to buy?

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Additional Practice

The Extra Practice Problems can be used as additional practice for homework, during an intervention block, etc. Daily Word Problems and Fluency Activities are aligned to the content of the unit but not necessarily to the lesson objective, therefore feel free to use them anytime during your school day.

Word Problems and Fluency Activities

Word Problems and Fluency Activities

Help students strengthen their application and fluency skills with daily word problem practice and content-aligned fluency activities.

Next

Divide three-digit dividends by two-digit divisors with one-digit quotients and remainders in the ones place.

Lesson 16
icon/arrow/right/large

Lesson Map

A7CB09C2-D12F-4F55-80DB-37298FF0A765

Topic A: Writing and Interpreting Numerical Expressions

Topic B: Multi-Digit Whole Number Multiplication

Topic C: Multi-Digit Whole Number Division

Request a Demo

See all of the features of Fishtank in action and begin the conversation about adoption.

Learn more about Fishtank Learning School Adoption.

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Yes

No

Any other information you would like to provide about your school?

We Handle Materials So You Can Focus on Students

We Handle Materials So You Can Focus on Students

We've got you covered with rigorous, relevant, and adaptable math lesson plans for free