Lesson 5

Model Repeated Addition and Subtraction

Est. Class Sessions: 2–3
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Mathematical Standards

1.OA.A
Represent and solve problems involving addition and subtraction. (1.OA.A.1)
1.MD.C
Represent and interpret data. (1.MD.C.4)
1.NBT.C
Use place value understanding and properties of operations to add and subtract. (1.NBT.C.4)

Standards for Mathematical Practice

MP2.
Reason quantitatively.
MP3.
Construct viable arguments and critique the reasoning of others.
MP7.
Look for and make use of structure.
MP8.
Look for and express regularity in repeated reasoning.

Students solve problems from stories and drawings involving multiplication and division concepts with repeated addition and subtraction strategies.

Content in this Lesson

  • Representing repeated addition and repeated subtraction using counters and drawings [E2].
  • Solving repeated addition and repeated subtraction problems using drawings, skip counting, and invented strategies [E3].
  • Reading a table to make predictions and solve problems [E7].
  • Knowing what is important to solve a problem [MPE1].
  • Finding strategies to solve problems [MPE2].
  • Showing or telling how to solve problems [MPE5].
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Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Books
Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

desk number line (0–40)
30 connecting cubes, optional
crayons
9" X 12" white or light-colored construction paper

Materials for the Teacher

Display of Duck in Boots (Student Activity Book) Page 475
Display of Number of Math Mice Features Master (Teacher Guide)
Display of 100 Chart (Student Activity Book) Reference
Unit 14 Assessment Record
Math Facts Class Record
class number line (0–130)
Display of a "Math Mouse." See Materials Preparation.

Materials Preparation

Draw a Math Mouse. For Parts 2 and 3, prepare a drawing of a "Math Mouse." Draw your sample Math Mouse with colored markers to show a triangle with 3 gray lines, 6 black whiskers, 5 red dots for the mouth, 2 blue dots for eyes,
1 brown tail, and 1 pink nose. You can be more creative by using toothpicks, yarn, stickers, or other materials but it is important to use multiples of 2, 3, and 5 for different features. See Figure 1 for a sample Math Mouse.



Figure 1: Sample math mouse

Assessment in this Lesson

Assessment Expectation Assessed Math Practices
Expectation Assessed
Squid Squares
with Feedback Box
Student Activity Book
Pages 479–481
E2.
Represent repeated addition and repeated subtraction using counters, drawings, and number sentences.
E3.
Solve repeated addition and repeated subtraction problems using drawings and invented strategies.
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.
MPE5.
Show my work. I show or tell how I arrived at my answer so someone else can understand my thinking.
DPP Item R
Rule Machine
Teacher Guide - digital
E2.
Represent repeated addition and repeated subtraction using counters, drawings, and number sentences.
E3.
Solve repeated addition and repeated subtraction problems using drawings, skip counting, and invented strategies.
E6.
Identify and describe patterns in addition and subtraction problems represented in a rule machine.

Vocabulary in this Lesson