Lesson 8

Check It Out

Est. Class Sessions: 2
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Mathematical Standards

2.MD.B
Relate addition and subtraction to length. (2.MD.B.6)
2.OA.A
Represent and solve problems involving addition and subtraction. (2.OA.A.1)
2.NBT.A
Understand place value. (2.NBT.A.1)
2.NBT.B
Use place value understanding and properties of operations to add and subtract. (2.NBT.B.7)

Standards for Mathematical Practice

MP1.
Make sense of problems and persevere in solving them.
MP2.
Reason quantitatively.
MP3.
Construct viable arguments and critique the reasoning of others.
MP4.
Model with mathematics.
MP5.
Use appropriate tools strategically.
MP6.
Attend to precision.

In the Adventure Book story, “Check It Out,” Marcus solves a problem in the grocery store with strategies he uses in math class. Students use a variety of strategies to solve grocery store problems. After solving an assessment problem two ways, students use a checklist to check their own work.

Content in this Lesson

  • Representing addition and subtraction using multiple representations (e.g., stories, drawings, diagrams, counters, number sentences, number lines,
    200 Chart) [E3].
  • Finding addition and subtraction strategies to solve problems [MPE2].
  • Checking for reasonableness [MPE3].
  • Communicating solution strategies [MPE5].
  • Using labels to show what numbers mean [MPE6].
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Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Book

 Student Activity Book
Adventure Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

connecting cubes
desk number line (0–100)
collection of coins

Materials for the Teacher

Display of Math Practices (Student Activity Book) Reference
Display of Self-Check: Checklist from Two Solutions (Student Activity Book) Page 160
Unit 3 Assessment Record
class number line (0–130)
green pepper, optional. See Materials Preparation.
object that weighs about 1 pound, e.g., loaf of bread, optional. See Materials Preparation.

Materials Preparation

Gather Benchmarks for Estimating Weight (optional). Gather some items to give students benchmarks for estimating weight. In the story, students estimate the weight and the price of a green pepper. It might be helpful to have a green pepper and an object that weighs about one pound, such as a loaf of bread.

Assessment in this Lesson

Assessment Expectation Assessed Math Practices Expectation Assessed
Two Solutions
and Self-Check: Checklist
Student Activity Book
Pages 159–160
E3. 
Represent addition and subtraction using multiple representations (e.g., stories, drawings, diagrams, counters, number sentences, number lines, 200 Chart).
MPE2. 
Find a strategy. I choose good tools and an efficient strategy for solving the problem.
MPE3. 
Check for reasonableness. I look back at my solution to see if my answer makes sense. If it does not, I try again.
MPE6. 
Use labels. I use labels to show what numbers mean.

Vocabulary in this Lesson