Shona Gilmer
MAED 3224
October 24, 2012
Lesson Plan-IMB
Grade Level/Subject: 3rd /Math
Topic: Fact Families
Behavioral Objective: Given a fact family handout students accurately complete 13 out of 15
problems.
CCSS: 3BNT. 2 Fluently add and subtract within 1000 using strategies and algorithms based on
place value, properties of operations, and/or the relationship between addition and subtraction.
Prerequisite Knowledge and Skills: Students should be skilled in addition and subtraction.
Materials/Resources: Cooperating teacher
Rationale: Students should learn how to properly add and subtract within fact families to be able
to recognize how addition and subtraction problems are interchangeable.
Focus/Review: Show students a math problem using the smartboard such as 4+6= _ and have
them solve the addition problem. Then write the problem 10-6=_ on the board and have them
solve. Ask students if they see any similarities in these two problems?
Objective as stated for students: Today we are going to learn about fact families. Fact families
are important because they will help you understand the similarities between addition and
subtraction and how they are related. After I teach you about fact families you will be able to
accurately complete an activity sheet with various fact family problems.
Teacher Input: Tell students “that fact families are a group of numbers that are related to each
other. The numbers in a fact family can be combined to create a number of equations. We know
that it is important to quickly solve addition combinations with small numbers when you are
solving addition problems with larger numbers. It is also important because these combinations
can help you solve related subtraction problems with smaller numbers which we call subtraction
facts.” Show students two sets of unifix cubes that are two separate colors. The green set will
include 5 cubes and the red set will include 4 cubes. Say “to find out what a part of this fact
family is we are going to add these cubes together. Here we have 5 green cubes and 4 red cubes.”
While holding and showing the cubes to the students the say “we have a part and part which
equal a whole.” Connect the cubes and count how many cubes you now have total. Tell students
that the sum of 5+4 is equal to 9.
Then say “now I need to find the second part to my fact family. I want to subtract the cubes to
turn them back into parts. I have 9 cubes total because I have 5 green and 4 red so that means
that I need to subtract 4 cubes to find the difference.” Take the 4 red cubes away and tell students
that “we had 9 cubes total and took 4 away therefore the difference is equal to 5.”
On the smartboard draw a “fact family house”. Tell students that “you are going to use addition
and subtraction to fill in the fact family living in the house.” In the first house at the top write the
number 13, in the left hand corner write the number 8, and in right hand corner write the number
5. A plus and minus will go in the middle. Then begin to fill in the lines in the house and tell
students that “we will use all three of these numbers to help us form different addition and
subtraction equations. The first blank I see is an addend plus an addend equal to the sum.
Therefore I am going to take the 8 and write it in the first blank. Then I will take the 5 and write
it in the second blank. Then I will ask myself what is 8 + 5 equal to and I will write 13 in the
blank. Repeat this for the rest of the equations.
Now we are going to use number triangles to help us find fact families. When using number
triangles you will follow the same steps as we did in the fact family house example. We will
write our three numbers in the triangle and then we will find the addends and the subtraction
facts using equations. In the triangle write the numbers 10, 7, and 3. Fill in the blanks for the
addition and subtraction problems.
Next we are going to find fact families using just the 3 numbers. Write the numbers 65, 122, and
57 on the board. Then write the blanks for the different equations. Tell students that we are going
to first begin solving this problem by writing the number 65 in the blank. Then I am going to ask
myself which number am I going to use to give me the larger number? Write 65 in the blank.
This means that 57+65=122. Use the Hundreds, Tens, Ones method to add 65+57=122. Continue
this method to find the other fact families.
Guided Practice: Give students a handout with a variety of the different methods such as: the
fact family house, the triangle method, and just listing the numbers. Go over each problem with
students asking them to give the answers. For the fact family house use the numbers 13, 9, and 4
in the house and ask students to fill in the equations. For the triangle equation ask students what
the missing addends are for the numbers 12, 7, and 5. Then ask them to fill in the numbers for
the subtraction facts. For the last example, have students find the missing addend/subtraction fact
for the numbers 75, 134, and 59. Ask students to give the answers to the different equations
while the teacher models on the board. Give the students the numbers 90, 147, and 57 and ask
students to fill in the answers for each equation.
Independent Practice: Give students a handout with the three different types of problems. Fact
family houses, the triangle method, and listing the numbers. Students will complete the handout.
Closure: Ask students what makes 3 numbers a fact family? What are some of the different
ways we can find fact families? What equations do we use to solve the fact families?
Evaluation: Students will be evaluated on the completion of the handout solving the different
types of fact families.
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Full Mastery- Students will need to have at least 13 out of the 15 total problems correct.
Partial Mastery- Students will need to have at least 8 out of the 15 problems correct.
No Mastery- (re-teaching needed) Students will have less than 8 out of the 15 problems
correct.
Plans for Individual Differences: For struggling students have students work with a partner to
solve equations on the handout. Have students use the unifix cubes to help them solve the fact
families.