Where is my Fact Family?
Students will be able to identify fact families and understand and the commutative property for addition and subtraction.
- Begin the lesson by reviewing the concept of a fact family.
- Explain that a fact family consists of all of the addition and subtraction combinations that two numbers and their sum can have. For example, 1 + 2 = 3, 2 + 1 = 3, 3 - 1 = 2, and 3 - 2 = 1 make up a fact family.
- Write on the board three numbers that can form a fact family (e.g. 3, 4, and 7).
- Ask students to construct the fact family formed by the numbers. After a few minutes, have them compare answers with one another.
- Call on volunteers to write down each of the four equations in the family. Make clarifications as needed.
Explicit Instruction/Teacher Modeling(10 minutes)
- Direct attention to the large dominoes posted around the classroom. Let the class know that these dominoes will be involved in an activity.
- Give each student an equation strip from Set 1. Explain that students will need to find the dominoes that match their equations.
- Demonstrate the exercise by selecting a strip, reading it aloud, then moving to its corresponding domino.
Guided Practice/Interactive Modeling(15 minutes)
- Give students about five minutes to find their dominoes. Once they finish gathering, there should be multiple students at each domino, with the exception of the 0 family domino.
- Ask students how many facts they think are in a fact family. Have them look around at how many students are at each domino before they respond.
- Explain that fact families usually contain four equations. When the addends of the family are the same, they contain two. The only exception is the 0 family, which only contains one.
- If there's enough time remaining, allow students to repeat the activity with equations from Set 2.
Independent Working Time(10 minutes)
- Have each student select one or two of the dominoes in the room.
- Ask students to copy down their dominoes on a sheet of paper and write down the fact families for those dominoes.
- Enrichment: Advanced students can be asked to complete the second round of the exercise without talking. Doing so pushes them to find the correct domino without getting help from one another.
- Support: Struggling students can be asked to find members of their fact families before searching for their dominoes. Once the family members are found and groups are formed, students can work together to look for the dominoes.
- Observe students as they complete the fact family exercise, making mental notes of common struggles that they face.
- Collect and evaluate the sheets that students worked on during Independent Working Time in order to assess their overall comprehension of the lesson content.
Review and Closing(5 minutes)
- Go over the definition of fact family once again.
- Allow students to ask questions and give comments about the lesson.