1. Grade 3 Module 1: Lesson 4
Engage NY Eureka Math

2. Today’s Learning Objective
“We will understand the meaning of the unknown as the size of the group in division.”
Today’s Learning Objective

3. Arrays
What is the repeated addition?

4. Arrays
What is the repeated addition?

5. Arrays
What is the repeated addition?
= 6

6. Arrays
3 x __ = __

7. Arrays
3 x 2 = 6

8. The chairs on the carpet are arranged in 3 rows of 5
The chairs on the carpet are arranged in 3 rows of 5. How many chairs are there in all?
Application Problem

9. The chairs on the carpet are arranged in 3 rows of 5
The chairs on the carpet are arranged in 3 rows of 5. How many chairs are there in all?
Application Problem

10. The sit spots on the carpet are arranged in 3 rows of 5
The sit spots on the carpet are arranged in 3 rows of 5. How many sit spots are there in all?
Application Problem

11. Agenda Fluency Application Problem NEW LEARNING Problem Set
Exit Ticket

12. Materials: Container of Counters Whiteboard Whiteboard Marker
Division
Materials: Container of Counters Whiteboard Whiteboard Marker

13. the number of groups or the size of the group?
Division
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
Are we trying to find
the number of groups or the size of the group?

14. Division the size of the group
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
the size of the group

15. Division
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
Let’s pretend your counters are the markers and let’s divide your 18 counters into 2 equal groups.

16. Division
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me? Take out 18 of the counters and place them into 2 equal groups on your whiteboard. Draw a circle around each group.

17. Let’s write a division sentence for our work. What do we start with?
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
Let’s write a division sentence for our work. What do we start with?

18. The total number of markers is 18.
Division
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
We should start with 18
The total number of markers is 18.

19. Write the division sentence
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
Write the division sentence
for our work.

20. Division
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
18 ÷ 2
= 9

21. Division
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
18 ÷ 2
= 9
What is the size of the group?

22. Division
Yesterday, Ms. Cordova bought a new pack of 18 markers. She shared them with me by dividing them into 2 equal groups. Now, I have a bunch of new markers for our classroom. How many did she give me?
18 ÷ 2
= 9
The group size is 9.
She gave me 9 markers.

23. Remember!
In division, we ALWAYS start with the total because… that is what we are dividing!

24. What if Ms. Cordova had 15 markers to share with Mrs. Palmer and I ?
More Practice!

25. What if Ms. Cordova had 15 markers to share with Mrs. Palmer and I?
More Practice!
Let’s pretend your counters are the markers and let’s divide your 15 counters into 3 equal groups.

26. What if Ms. Cordova had 15 markers to share with Mrs. Palmer and I?
More Practice!
Let’s write a division sentence to go with that. What should we start with?

27. 15 More Practice! What if Ms. Cordova had 15 markers to share with me?
There are 15 total markers.

28. What if Ms. Cordova had 15 markers to share with Mrs. Palmer and I?
More Practice!
Count out 15 counters and place them into 3 equal groups on your whiteboard.
Draw a circle around each group.

29. What if Ms. Cordova had 15 markers to share with Mrs. Palmer and I ?
More Practice!
Write a division sentence to
match your drawing.

30. What if Ms. Cordova had 15 markers to share with Mrs. Palmer and I ?
More Practice!
15 divided by 3 is 5
Is 5 the number of groups
or the group size?

31. What if Ms. Cordova had 15 markers to share Mrs. Palmer and I ?
More Practice!
5 is the group size.

32. What if Ms. Cordova had 15 markers to share with Mrs. Palmer and I ?
More Practice!
Each teacher gets 5 markers.

33. How are multiplication and division the same?
Partner Talk:
How are multiplication and division the same?

34. Problem Set

36. Problem Set Debrief