One of the most common complaints I hear from other teachers is, “Many of my students still don’t know their basic facts.” It can be exasperating to see a fourth grader still counting on his/her fingers when trying to add two numbers together – let alone multiply or divide. Let’s face it, learning the basic addition/subtraction and multiplication/division facts is an absolute requirement for a math student to be able to achieve success. This article describes one way of teaching addition/subtraction fact families to second or third graders.
One easy and enjoyable activity is what I call the “Fact Family Triangle”. Before beginning the activity, I tell students that a fact family is made up of three numbers. Only those three numbers can be in a particular family. The three numbers are related to each other because of addition and subtraction. The fact family all live together in a three sided home (I draw a large triangle on the board). I then ask a student to give me a number from 1 – 9, and I write the number in one corner of the triangle. I ask another student to give me a different number from 1 – 9, and write that number in another corner of the triangle. I remind the students that this particular fact family only allows addition and subtraction in their home, and ask them which number is missing in the other corner. Let’s say the numbers given were six and five. In this case, there would be two correct answers, 11 or one. I always use the first correct answer that is offered. When I get a correct answer, I ask the student to explain why that number belongs in the fact family. Most students use addition, but some go with subtraction. Either one is fine. Finally, I set up two addition equations and two subtraction equations underneath the triangle, and ask students to help me correctly fill in the fact family numbers.
We’ll assume that 11 was the number given, so the four equations would look like this:
5 + 6 = 11
6 + 5 = 11
11 – 6 = 5
11 – 5 = 6
If one was the number given, the equations would look like this:
1 + 5 = 6
5 + 1 = 6
6 – 5 = 1
6 – 1 = 5
Using fact families gives you “more bang for your buck,” because you are encouraging students to use advanced properties of addition and subtraction, and you are getting them to learn four facts at a time – not just one! The more they do this, the more they will see how the numbers are related to each other. Below are some other lessons on fact families that I believe you will enjoy.
Addition and Subtraction Fact Family Lesson Plans:
Students create a fact family town out of triangular-shaped houses in order to develop an understanding of numbers which are "related" in fact families. This lesson lends itself well to creating a bulletin board display of the fact family town.
Students use pictures of themselves and their classmates (taken in class), to create fact families. For example, a picture of a group of three students plus a picture of a group of four students equals seven students. This wonderful lesson allows students to use their own pictures to create addition and subtraction number sentences.
Students explore the relationship between addition and subtraction through listening to books and using links of chain to act out what is happening, mathematically, in the story. This innovative lesson nicely ties language arts and mathematics together into a very engaging and meaningful learning experience.
Students use pieces of pasta on a paper plate to explore how addition and subtraction are related. In this motivating lesson, students use pieces of macaroni as a manipulative in order to create different sets of four fact family sentences.