Lesson 9

Workshop: Reasoning from Known Facts

Est. Class Sessions: 2
X

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.MD.B
Relate addition and subtraction to length. (2.MD.B.6)

Standards for Mathematical Practice

MP2.
Reason quantitatively.
MP5.
Use appropriate tools strategically.
MP6.
Attend to precision.
MP8.
Look for and express regularity in repeated reasoning.

Students revisit games and representations encountered earlier in the unit to practice using reasoning strategies to solve addition facts.

Content in this Lesson

  • Representing addition situations using number sentences and ten frames [E1].
  • Using mental math strategies and reasoning strategies (e.g., using doubles, making ten) to solve addition problems within 20 [E2].
X

Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Book

 Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

connecting cubes

Materials for the Teacher

2 prepared display sets of 0–10 Small Ten Frame Cards Masters from Lesson 5 (Teacher Guide)
Display of Tens Game Master (Teacher Guide)
2 prepared display sets of Number Cards 0–19 Masters (Teacher Guide)
Prepared sets of the Number Cards 0–10 Masters from Lesson 5 (Teacher Guide). See Materials Preparation.
Prepared sets of the Doubles and Near Doubles Ten Frames Cards Masters from Lesson 6 (Teacher Guide). See
    Materials Preparation.
Doubles and Near Doubles Bump from Lesson 6 (Student Activity Book) Pages 29–31. See Materials Preparation.
Prepared sets of the 0–10 Small Ten Frame Cards from Lesson 5 (Teacher Guide). See Materials Preparation.
Prepared sets of the Number Cards 0–19 Masters (Teacher Guide). See Materials Preparation.
Display of the Reasoning Strategies Practice Menu (Student Activity Book) Page 59
Unit 1 Assessment Record
Unit 1 Individual Assessment Record
Math Facts Class Record
connecting cubes
clear plastic spinner or paper clip and pencil
scissors
envelopes or resealable bags

Materials Preparation

Prepare Material for Centers. Students will have access to several different center activities in this lesson. Make a sign to identify each center activity. Decide how many students will visit a center at one time and prepare the following materials for each activity accordingly. Place them in a learning center.

  • Ten Frame Flash: 2 prepared sets of the 0–10 Small Ten Frame Cards Masters from Lesson 5 per student pair
  • Play Make Ten: 4 prepared sets of Number Cards 0–10 Masters from Lesson 5 per student pair
  • Play Tens Game: 1 prepared set of Number Cards 0–19 Masters per student
  • Doubles and Near Doubles Ten Frame Cards: 1 prepared set of Doubles and Near Doubles Ten Frames Cards Masters from Lesson 6 per student group
  • Doubles and Near Doubles Bump. Spinners and game board from the Doubles and Near Doubles Bump pages in the Student Activity Book in Lesson 6, connecting cubes in two colors, and one clear plastic spinner per student pair

Meeting Individual Needs

You should have collected and saved the Doubles and Near Doubles Bump pages from Lesson 6 to supply this learning center. As students finish the game in Lesson 6, collect all the materials into a large bag so all the materials are ready for Lesson 9 or other times you would like students to play this game.

Assessment in this Lesson

Assessment Expectation Assessed
Reasoning Strategies Practice Menu
Self-Check
Student Activity Book
Page 59
E1.
Represent addition and subtraction situations using multiple representations (e.g., stories, drawings, counters, number sentences, number lines, diagrams, ten frames).
E2.
Use mental math strategies and reasoning strategies (e.g., using doubles, making ten) to solve addition and subtraction problems within 20.
Reasoning from Known Facts
Student Activity Book
Pages 61–64
E2.
Use mental math strategies and reasoning strategies (e.g., using doubles, making ten) to solve addition and subtraction problems within 20.
DPP Item FF
Fact Families
E7.
Demonstrate fluency with the addition facts in Group A (0 + 1, 1 + 1, 2 + 1, 3 + 1, 0 + 2, 2 + 2, 3 + 2, 4 + 2) and Group B (3 + 0, 4 + 0, 4 + 1, 5 + 1, 6 + 1, 5 + 2, 6 + 2, 5 + 3, 7 + 1, 1 + 8).
E8.
Determine the unknown number in an addition or subtraction sentence relating three whole numbers for the facts in Groups A and B.
DPP Item GG
Addition with Zeros and Ones
E7.
Demonstrate fluency with the addition facts in Group A (0 + 1, 1 + 1, 2 + 1, 3 + 1, 0 + 2, 2 + 2, 3 + 2, 4 + 2) and Group B (3 + 0, 4 + 0, 4 + 1, 5 + 1, 6 + 1, 5 + 2, 6 + 2, 5 + 3, 7 + 1, 1 + 8).
DPP Item HH
Pockets
E7.
Demonstrate fluency with the addition facts in Group A (0 + 1, 1 + 1, 2 + 1, 3 + 1, 0 + 2, 2 + 2, 3 + 2, 4 + 2) and Group B (3 + 0, 4 + 0, 4 + 1, 5 + 1, 6 + 1, 5 + 2, 6 + 2, 5 + 3, 7 + 1, 1 + 8).
E8.
Determine the unknown number in an addition or subtraction sentence relating three whole numbers for the facts in Groups A and B.

Vocabulary in this Lesson