Curriculum  /  Math  /  2nd Grade  /  Unit 5: Adding and Subtracting Within 1,000  /  Lesson 15

Adding and Subtracting Within 1,000

Lesson 15

Math

Unit 5

2nd Grade

Lesson 15 of 25

Objective

Use concrete manipulatives to subtract within 1,000 with up to one decomposition.

Student-Facing

I can use base ten blocks to represent subtraction with up to one decomposition of a larger unit. 

Common Core Standards

Core Standards

  • 2.NBT.B.7 — Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.

Foundational Standards

  • 1.NBT.B.2
  • 2.NBT.A.1
  • 2.NBT.A.2

Criteria for Success

  1. Build a three-digit numbers to represent hundreds, tens, and ones for minuend in the problem with base ten blocks.
  2. If there are not enough tens to subtract, remodel the minuend or whole by decomposing a hundred into 10 tens and remodel the whole number as a sum of hundreds, more than 10 tens, and ones to subtract. 
  3. If there are not enough ones to subtract, remodel the minuend or whole by decomposing a ten and remodel the number as a sum of hundreds, tens, and more than 10 ones to subtract. 
  4. Subtract units by place value to find the difference.
  5. Explain if and why a problem required a decomposition of a larger unit in order to subtract.

Tips for Teachers

  • Up to this point, students have only decomposed a ten in order to subtract. This lesson focuses on decomposing a hundred into 10 tens in order to subtract.
  • In the previous lesson's Target Task, if data suggests that students need support with subtraction in situations where they need to decompose a ten to subtract, provide some concrete manipulative practice before the start of this lesson. 

Lesson Materials

  • Base ten blocks (10 hundreds, 18 tens, 18 ones per student)
  • Hundreds place value chart (1 per student) — Work Mat Template — These should be laminated or in sheet protectors to reuse

Warm Up

5-10 minutes

Unlock warm-up activities that help you engage every student and prepare them for the day’s lesson with a Fishtank Plus subscription.

Anchor Tasks

15-25 minutes

a.   Build the number 210 with hundreds and tens base ten blocks.

  1. How many hundreds and tens base ten blocks did you use?
    _____ hundreds _____tens

  2. In order to subtract 50, how would you remodel your base ten blocks to be able to subtract 50?
    _____ hundreds _____ tens

b.   Use a place value work mat and base ten blocks to solve. Record your answers.

  1. 358 - 42 = _____

    Did you decompose a larger unit to subtract?  Explain your thinking.

  2. 415 - 133 = _____

    Did you decompose a larger unit to subtract?  Explain your thinking.

  3. 237 - 128 = _____

    Did you decompose a larger unit to subtract?  Explain your thinking.

Purpose

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

Upgrade to Fishtank Plus to view Facilitation Guidance and Sample Student Response for this Anchor Task.

Problem Set

15-20 minutes

Target Task

5-10 minutes

Use a place value work mat and base ten  blocks to solve. Record your answers. 

a.   648 - 52 = _____

Did you decompose a larger unit to subtract?  Explain your thinking.

b.   729 - 261 = _____

Did you decompose a larger unit to subtract?  Explain your thinking.

c.   365 - 164 = _____

Did you decompose a larger unit to subtract?  Explain your thinking.

Student Response

Additional Practice

Daily Word Problems, Warm Ups, and Center 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

Next

Use concrete manipulatives to subtract within 1,000 with up to two decompositions.

Lesson 16
icon/arrow/right/large

Lesson Map

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

Topic A: Adding with Mental Strategies

Topic B: Adding within 1,000

Topic C: Subtracting with Mental Strategies

Topic D: Subtracting within 1,000

Topic E: Story Problems and Explaining Addition and Subtracting Thinking

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