Heather Breaux
3rd. Grade
Division Unit
Lesson 7: Dividing with 1 and 0
Date:
Approximate Time: 60 minutes

Berks County Standards:
1. 2.1.3 Numbers, Number Systems and Number Relationships- C. Represent equivalent forms of the same number through the use of concrete objects, drawings, word names and symbols.
2. 2.1.3 Numbers, Number Systems and Number Relationships- L. Demonstrate knowledge of basic facts in four basic operations.
3. 2.2.3 Computation and Estimation- D. Demonstrate concept of division as repeated subtraction and as sharing.

NCTM Standards:
1. Number and Operations
7. Reasoning and Proof
8. Communication

Behavioral Objectives: Upon completion of this lesson, students will be able to….
1. Divide with 1 and 0

Materials/Technology Needs: 5 enlarged tomatoes; textbooks; dry erase boards and markers; WS “Check” on p. 263.

Anticipatory Set: Place 5 enlarged tomatoes on the board in a group and read the “Alternative Teaching Strategy” found on p. 262B: “Brad’s garden has 5 tomato plants, divided among 5 rows. How many plants are in each row?” Have students agree upon how to arrange the plants on the board until they are showing what the problem asks. Ask for a volunteer for the division sentence that this problem is using, having them explain what each number means in the problem. Once the sentence is answered, ask, “What happens when the dividend and divisor are the same?” (the quotient is 1). Go on to say, “Suppose I take away all of the tomato plants (remove all plants from board). How many tomato plants are now in Brad’s garden?” (0). “Our new problem has us divide the 0 plants into 5 rows. How many plants now are in each of the rows?” (0 plants). Have a student come up to write the new division sentence, giving them assistance if need be (0 ÷ 5= 0).

Procedure:
1. Have the students open their textbooks to p. 262 for the “Moo…ve Over” exercise that explains the rules for dividing with 1 and 0.
A. Rule A: Read box aloud and have students echo read the number of cows, stalls, and number of cows in each stall. Follow this by visually representing this rule by using 3 students and have them sit on top of each other on 1 chair- emphasize safety!!!!
B. Rule B: Read box aloud and have 3 different students with 3 different chairs visually represent this rule.
C. Rule C: Read box aloud. Visualize by using 0 students and 3 chairs.
D. Rule D: Read aloud and explain to class that you can’t divide by 0 because it’s impossible to do this. Zero can never be the divisor in a division problem. Have them think of it in another way: Write 4 ÷ 0= ? on the board. Ask, “What number can I multiply times 0 to get 4?” This isn’t possible, which is why 0 can’t be a divisor.
2. Divide students in small groups of 3-5 students. Ask each group to come up with a new example, assigning each group one of the Rules. Repeat exercise but switch the rules for each group.
3. Pass out WS “Check” on p. 263. Do problems 1-9 as a class together to make sure students are comprehending the lesson and are on track. Questions 10-39 are to be done in pairs or on an individual basis, depending on how well the students are feeling about it.
4. Explain to the students that it is their homework assignment to come up with and record on a piece of paper an example for Rules A, B, and C.

Accommodations Jessica will be seated at the front of the room so that she can see all problems on the board. I will provide her with enlarged worksheets to work with at her desk.

Closure: Have the students take out their dry erase boards to answer the following problems: 6÷6= 1; 0÷6=0; 9÷1=9; 6÷1=6; 0÷4=0; 7÷7=1.

Key Questions:
1. “What does any number divided by one equal?”
2. “Why does any number (except 0) divided by itself equal 1?”
3. “Why can 0 never be a divisor?”

Evaluation: I will be using the students examples for Rules A-C that they present in class and the “Check” worksheet problems 1-9 as my formative assessment. The students’ homework assignment will be used as their summative assessment for the day.

Assignment: Examples problems for Rules A, B, and C.


Resources Used:
1. (2004). Harcourt Math Teacher Edition: Third Grade. Vol. 2.) Harcourt, Inc.


Frank D'Angelo, who submitted these articles, writes: [This] is an excellent unit submitted by a student in my Elementary Mathematics Methods Course.