Lesson 9

Fact Families

Est. Class Sessions: 1
X

Mathematical Standards

1.OA.B
Understand and apply properties of operations and the relationship between addition and subtraction. (1.OA.B.3)
1.OA.C
Add and subtract within 20. (1.OA.C.6)
1.OA.D
Work with addition and subtraction equations. (1.OA.D.8)

Standards for Mathematical Practice

MP1.
Make sense of problems and persevere in solving them.
MP2.
Reason quantitatively.
MP8.
Look for and express regularity in repeated reasoning.

Students find fact families while using strategies that apply the properties of addition and subtraction such as the commutative property (turn-around facts), properties of zero, and the inverse relationship between addition and subtraction. Students use counting on and counting back strategies to solve facts from Groups A and B.

Content in this Lesson

  • Using strategies that apply the properties of addition (e.g., turn-around, zero) to solve addition and subtraction problems [E4].
  • Adding and subtracting within 10 using strategies (counting on, counting back, zero) [E7].
  • Using mental math strategies to add for the facts in Groups A and B [E8].
  • Finding the related subtraction sentence for an addition sentence (e.g., fact families) [E3].
  • Finding the unknown whole number in an addition or subtraction equation relating three whole numbers [E5].

Daily Practice and Problems CC–DD

CC. Even or Odd

DD. At the Pet Shelter

X

Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Book

 Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Student Pairs

20 connecting cubes, 10 of one color and 10 of another color
desk number line (0–40)

Materials for the Teacher

Display of Part-Whole Diagram and Number Sentences Master from Lesson 6 (Teacher Guide)
Unit 6 Assessment Record
Unit 6 Individual Assessment Record
Sorting Mat chart showing sums from Lesson 1
Sorting Mat chart showing differences from Lesson 8
Addition Strategies chart from Lesson 1
connecting cubes
class number line (0–130)
chart paper

Materials Preparation

Prepare Connecting Cubes. Students will each need 20 connecting cubes, 10 of one color and 10 of another color. The colors that students have do not all have to be the same. For example, one student could have blue and green cubes and another could have red and yellow cubes. It helps to have two different colors to show the distinct parts or addends when modeling a problem.

Prepare Fact Families Masters. There are 6 different pages of Fact Families Masters. Each student pair will need one of the Masters.

Assessment in this Lesson

Assessment Expectation Assessed
Fact Families Practice
Student Activity Book
Pages 163–164
E3.
Find the related subtraction sentence for an addition sentence (e.g., fact families).
E5.
Find the unknown whole number in an addition or subtraction equation relating three whole numbers.