Lesson 3

Use Problem-Solving Strategies

Est. Class Sessions: 2
X

Mathematical Standards

1.NBT.C
Use place value understanding and properties of operations to add and subtract. (1.NBT.C.4)

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.
MP5.
Use appropriate tools strategically.

Students use intervals to estimate answers to problems and continue to identify and use a variety of tools and strategies to solve problems. Students think about how they can modify the strategies they learned for solving problems with small numbers to solve problems with larger numbers.

Content in this Lesson

  • Using the relationship between addition and subtraction to solve problems.
  • Using mental math strategies to solve addition and subtraction problems with larger numbers (e.g., 2 digit + 1 digit) [E4].
  • Estimating sums and differences using ten as a benchmark [E5].
  • Knowing what is important to solve a problem [MPE1].
  • Finding strategies to solve problems [MPE2].
  • Checking for reasonableness [MPE3].
  • Showing or telling how to solve problems [MPE5].
X

Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Books
Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

20 connecting cubes
desk number line (0–40)

Materials for the Teacher

Display of Questions 1–2 on the Solve Problems with Larger Numbers (Student Activity Book) Pages 461–462
Display of Addition Strategies Menu for Larger Numbers (Student Activity Book) Reference
Display of Subtraction Strategies Menu (Student Activity Book) Reference
Display of 100 Chart (Student Activity Book) Reference
Display of Ten Frames Master (Teacher Guide)
Display of Math Practice (Student Activity Book) Reference
Unit 14 Assessment Record
Math Facts Class Record
chart paper
class number line (0–130)
connecting cubes

Materials Preparation

Prepare a Display of a Chart with Intervals of Ten. Prepare a chart with 5 columns and label the columns with the following intervals: 1–10, 11–20, 21–30, 31–40, and 41–50. See Figure 1.



Figure 1: Chart with intervals of ten

Assessment in this Lesson

Assessment Expectation Assessed Math Practices
Expectation Assessed
Solve Problems with Larger Numbers
Check-In: Questions 3–4
with Feedback Box
Student Activity Book
Pages 463–465
E1.
Represent addition and subtraction problems using counters, number lines, ten frames, drawings, or number sentences.
E4.
Use mental math strategies to solve addition and subtraction problems with larger numbers (e.g., 2 digit + 1 digit).
E5.
Estimate sums and differences using ten as a benchmark.
MPE1.
Know the problem. I read the problem carefully. I know the questions to answer and what information is important.
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.
MPE5.
Show my work. I show or tell how I arrived at my answer so someone else can understand my thinking.
DPP Item J
Missing Numbers
Teacher Guide - digital
E8.
Demonstrate fluency with the addition facts with sums to ten in Group C (1 + 9, 2 + 7, 2 + 8, 3 + 6, 3 + 7, 4 + 6, 5 + 5).

Vocabulary in this Lesson