### Lesson plan

# Fact Family Trees

How are different math facts related? Let’s talk about it in the Fact Family Trees lesson! This math lesson plan is perfect for first graders who are learning about subtraction within 20, addition within 20, and inverse operations. Teachers are provided with worksheets that break down addition and subtraction fact families and are encouraged to ask students how equations in fact families are similar or different. As a final activity, students will draw fact family trees on their own to show how three different numbers can be related.

#### Learning Objectives

Students will be able to write related facts.

#### Introduction

*(5 minutes)*

- Write the following problems on the board:
**3 + 4 = 7****4 + 3 = 7****7 - 4 = 3****7 - 3 = 4**

- Ask students to turn to a partner and share what they notice about the facts.

#### Explicit Instruction/Teacher modeling

*(10 minutes)*

- Tell students that the facts on the board are in the same fact family.
**Fact families**are math facts that are related. Fact families use the same numbers but can use both addition and subtraction. - Draw seven circles on the board, three in one color and four in another. Walk through visualizing each of the facts you listed on the board, showing how three plus four is seven, seven take away three is four, etc.
- Explain that this fact family is made up of the numbers 3, 4, and 7. Write the numbers above the facts on the board.
- Draw a tree shape with the numbers 3, 4, 7 at the top of the tree and the facts in the trunk. Tell students that sometimes people make family trees to show their relatives. Fact family trees can show how the same numbers can come together to make related facts!

#### Guided Practice

*(5 minutes)*

- Draw a new tree on the board. Write the numbers 5, 1, 6 at the top.
- Have students turn to a partner and share as many facts that they can think of that use all three numbers. Tell students there are four possible facts to come up with.
- Ask students to share the facts they thought of with the class. Write the four related facts in the tree trunk on the board.

#### Independent working time

*(20 minutes)*

- Hand out the paper to each student. Have them draw trees with a fact family in them. Support students as needed to start with the right three numbers. Allow them to guess and check as needed to realize how to come up with numbers that work together.
- When students finish, hand out the Frosty Fact Families: Addition and Subtraction worksheets for students to complete.

#### Differentiation

**Support:**

- Have students work with a partner to create a fact family tree.
- Give students the three numbers to work with when creating their fact family trees.

**Enrichment:**

- Have students create multiple fact family trees.
- Challenge students to use bigger numbers.

#### Assessment

*(5 minutes)*

- Ask students to post their fact family trees around the room.
- Have students circulate around the room to look at each other's work while you assess student understanding.

#### Review and closing

*(5 minutes)*

- Call on a couple students to reflect on the work they saw around the room.
- Ask students to share what they learned about fact families.