1. Using mental math to divide
Literature Link: One Hundred Hungry Ants by Elinor Pinczes
Using mental math to divide
Lesson 9-1
CCSS 4.NBT.6, 4.OA.3

2. MATH Essential Questions
What strategies
can be used to
divide?
MATH
Essential
Questions

3. MATH Essential Questions
What are different meanings of division?
MATH
Essential
Questions

4. MATH Essential Questions
How can mental math and estimation be used to divide?
MATH
Essential
Questions

5. Warm up
Solve: 4,
5, ,986
11, ,561

6. Think and write
How did you learn your basic division facts?

7. Today’s Lesson
In this lesson, you will use basic facts and patterns to solve division problems.
Let’s look at the Envision Video for this lesson and take the quiz.

8. Solving division problems
Basic division facts can help you solve division problems. For example, let’s say you have 280 ÷ 4. If you know 28 ÷ 4, then you can solve it.
28 ÷ 4 = 7
280 ÷ 4 = 70
2800 ÷ 4 = 700
What pattern do you notice?

9. Sample problem
Example: Janet has 240 erasers. She decides to put an equal number of erasers into 6 plastic bags. How many erasers does she put into each bag?
Step 1: Think about the multiplication problem that might relate. 6 X ? = 24.
Step 2: Now, add a zero onto that number to make it a ten. 6 X ? = 240.
The answer is 40.

10. Practice!
63 ÷ 9
630 ÷ 90
42 ÷ 6
420 ÷ 60
32 ÷ 4
320 ÷ 40

11. More practice!
54 ÷ 6
540 ÷ 6
5400 ÷ 6
35 ÷ 7
350 ÷ 7
3500 ÷ 7

12. Problem 1
Mrs. Robson is dividing up pieces of candy for treat bags. She has 24 pieces of candy and 8 treat bags. How many pieces of candy should she put into each treat bag?
If Mrs. Robson got pieces of candy, how many pieces should she put into each of her 8 treat bags?

13. Problem 2
Helen bakes holiday cookies. She divides them equally among 8 plates. How many cookies does she put on each plate?

14. Problem 3
The snack stand at the fair sells 360 hot dogs. If they sold an equal number of hot dogs every day for 4 days, how many hot dogs did they sell each day?
If the snack stand sold hot dogs over 4 days, how many hot dogs did they sell each day?

15. Lesson Wrap Up
In this lesson, you used basic facts and patterns to solve division problems.
Reflection in Notebook: What I found helpful in today’s lesson was….
Center Activity – Teamwork (9-1).
Homework (9-1 Practice) for one “Paw Signature” and (9- 1 Reaching & Practice) if you want two “Paw Signatures.”
Website for Practice: Website for Practice: