Dots & Dots of Fact Families
Students will be able to form fact families.
- Show students a domino. Write the two numbers that the domino shows on the board.
- Now add up the two numbers and write the sum on the board.
- Ask students to come up with a number sentence that fits this domino.
Explicit Instruction/Teacher modeling(10 minutes)
- Tell students that the addition fact they came up with isn't the only fact that can be showed using the numbers on the dominoes. First, the addition fact can be written two ways: a + b = c or b + a = c. Write both addition sentences on the board.
- Explain that the three numbers can also be used to make subtraction sentences. On the board, write the two subtraction number sentences that can be made using the numbers on the dominoes.
- Tell students that facts that use the same three numbers are in the same fact family. Explain that you just wrote the "a, b, c fact family" on the board.
Guided Practice(5 minutes)
- Show another domino to the students. Write the two numbers the domino shows on the board. Have students add the numbers up to come up with the third number for their fact family.
- Have students turn to a partner and share as many facts 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 think of with the class. Write the four related facts on the board.
Independent working time(20 minutes)
- Hand out the Domino Fact Family and Domino Number Sentence worksheets to students.
- Model the steps to write the fact family for the first domino on the worksheet. Think aloud, "First I count the dots on the left side of the domino. Next, I write 12. Now, I count the dots on the right side. Since I am adding the dots, I write + 8. How many dots are there in all? Yes, 12 + 8 = 20."
- Have students work independently while you circulate around the room, lending help as needed.
- Have students work in a small, teacher-led group to complete the worksheets.
- Give students actual dominoes to use as manipulatives.
- Have students use dominoes to create additional fact families independently.
- Challenge students to explain how fact families work.
- Ask students to share their worksheets with a partner.
- As students present their work, circulate around the classroom to assess student understanding.
Review and closing(5 minutes)
- Ask students to turn to a partner and explain what a fact family is.
- Bring the class back together and ask for a few people to share their responses.