Lesson 2

Repeated Addition and Multiplication

Est. Class Sessions: 2
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Mathematical Standards

2.OA.A
Represent and solve problems involving addition and subtraction. (2.OA.A.1)
2.OA.B
Add and subtract within 20. (2.OA.B.2)
2.OA.C
Work with equal groups of objects to gain foundations for multiplication. (2.OA.C.4)
2.G.A
Reason with shapes and their attributes. (2.G.A.2)

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.
MP7.
Look for and make use of structure.
MP8.
Look for and express regularity in repeated reasoning.

A zoo kitchen is the context for solving multiplication problems. Students represent problems using tools or strategies that make sense to them and learn to differentiate between addition and multiplication situations.

Content in this Lesson

  • Representing multiplication problems using tiles, drawings, number lines, rectangular arrays, and number sentences [E2].
  • Making connections between repeated addition and multiplication [E3].
  • Distinguishing between addition and multiplication situations [E5].
  • Solving multiplication problems using strategies (e.g., skip counting, repeated addition) with tiles, drawings, number lines, rectangular arrays, and number sentences [E7].
  • Knowing what is important to solve a problem [MPE1].
  • Finding an efficient strategy for solving a problem [MPE2].
  • Showing or telling how to solve a problem [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

Teacher Resources

 Teacher Guide - digital

Supplies for Students

60 connecting cubes
desk number line (0–100)
construction paper work mat, optional

Materials for the Teacher

Display of Children’s Zoo Produce List Master (Teacher Guide)
Display of Math Practices (Student Activity Book) Reference
Display of Know the Problem (Student Activity Book) Pages 599–600
Unit 12 Assessment Record
Math Facts Class Record
60 connecting cubes
chart paper
12 pencils
3 pens

Materials Preparation

Prepare Strategy Charts. Create a chart for recording repeated addition strategies. Title the chart “Repeated Addition Strategies.” As students explain their strategies for solving the problems on the Children’s Zoo Produce pages in the Student Activity Book, list their strategies on the chart. Leave this chart on display throughout the rest of the unit.

Prepare Display of Word Problems. Write the following problems on chart paper to discuss the difference between multiplication and addition situations:

  1. Sara has 4 pencils and Jason has 3 pens. How many writing tools are there altogether?
  2. There are 4 students. Each student has 3 pencils. How many writing tools are there altogether?
  3. I have 3 blue crayons and 5 red crayons. How many crayons do I have altogether?
  4. I have 3 boxes. Each box has 5 crayons. How many crayons do I have altogether?

Assessment in this Lesson

Assessment Expectation Assessed Math Practices Expectation Assessed
Solve Zoo Problems
with Feedback Box
Student Activity Book
Pages 601–603
E2. 
Represent multiplication and division problems using tiles, drawings, number lines, rectangular arrays, and number sentences.
E3. 
Make connections between repeated addition and multiplication.
E5. 
Distinguish between addition and multiplication situations.
E7. 
Solve multiplication and division problems using strategies (e.g., skip counting, repeated addition) with tiles, drawings, number lines, rectangular arrays, and number sentences.
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.
MPE6. 
Use labels. I use labels to show what numbers mean.
DPP Item E
Missing Numbers
Teacher Guide - digital
E10.
Determine the unknown number in an addition or subtraction sentence relating three whole numbers for the facts in Group D.