Multiplication and Division, Part 2

Lesson 12

Math

Unit 3

3rd Grade

Lesson 12 of 23

Objective


Build fluency with multiplication and division facts using units of 8 and 9.

Common Core Standards


Core Standards

  • 3.OA.A.4 — Determine the unknown whole number in a multiplication or division equation relating three whole numbers. Determine the unknown whole number in a multiplication or division equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 × ? = 48, 5 = _ ÷ 3, 6 × 6 = ?
  • 3.OA.C.7 — Fluently multiply and divide within 100, using strategies such as the relationship between multiplication and division (e.g., knowing that 8 × 5 = 40, one knows 40 ÷ 5 = 8) or properties of operations. By the end of Grade 3, know from memory all products of two one-digit numbers.

Foundational Standards

  • 3.NBT.A.2
  • 3.OA.A.1
  • 3.OA.A.2

Criteria for Success


  1. Skip-count by eights.
  2. Skip-count by nines.
  3. Use mental strategies, such as making ten, to find unknown terms in the count-by sequence for eight and nine.
  4. Determine the unknown whole number in a multiplication or division equation relating three whole numbers, one of which is eight or nine, including equations where the unknown is represented with a letter.

Tips for Teachers


Lesson Materials

  • partially filled-in multiplication tables (1 per student) — These were started in Lesson 1 using a Blank Multiplication Table. See Anchor Task 3 for more information.
Fishtank Plus

Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.

Anchor Tasks

25-30 minutes


Problem 1

How many?

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 2

How many?

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

References

Flickr Photo: Sudoku correctly colored quilt by Darla

Sudoku correctly colored quilt by Darla by Darla is made available on flickr under a CC BY 2.0 license. Accessed Nov. 9, 2018, 3:43 p.m..

Modified by Fishtank Learning, Inc.

Problem 3

Determine the value of the unknown in each equation below.

a.   $$9 \times 8 = a$$

b.   $$63 = b\times 9$$

c.   $$48 \div c = 8$$

d.   $$7 = d\div 8$$

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 4

Here is the partially filled-in multiplication table from earlier lessons.

x 1 2 3 4 5 6 7 8 9 10
1 1 2 3 4 5 6 7 8 9 10
2 2 4 6 8 10 12 14 16 18 20
3 3 6 9 12 15 18 21 24 27 30
4 4 8 12 16 20 24 28 32 36 40
5 5 10 15 20 25 30 35 40 45 50
6 6 12 18 24 30 36 42 48 54 60
7 7 14 21 28 35 42 49 56 63 70
8 8 16 24 32 40 48 56     80
9 9 18 27 36 45 54 63     90
10 10 20 30 40 50 60 70 80 90 100

Add the new facts you encountered in this lesson to your multiplication table.  

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem Set

15-20 minutes


Discussion of Problem Set

  • Which pair of equations did you choose for #4? How do you know the other options aren’t correct? 
  • Which problems in #7 were the most difficult? Why? 
  • Let’s fill out more of the multiplication table based on what we’ve learned today. Do you notice anything about the 8 row/column in relationship with other rows/columns on the multiplication table? What about the 9 row?

Target Task

5-10 minutes


Problem 1

Wanda says she can count by 9 eight times to solve $$9\times8$$. Leroy says he can count by 8 nine times to solve this problem. Who is correct? Explain your answer. Include the product in your answer. 

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 2

Determine the value of the unknown in each equation below.

a.   $$a\times 8 = 48$$

b.   $$63 \div b =9$$

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Additional Practice


The Extra Practice Problems can be used as additional practice for homework, during an intervention block, etc. Daily Word Problems and Fluency Activities are aligned to the content of the unit but not necessarily to the lesson objective, therefore feel free to use them anytime during your school day.

Word Problems and Fluency Activities

Word Problems and Fluency Activities

Help students strengthen their application and fluency skills with daily word problem practice and content-aligned fluency activities.

Next

Use the associative property as a strategy to multiply by units of 8 and 9.

Lesson 13
icon/arrow/right/large

Lesson Map

A7CB09C2-D12F-4F55-80DB-37298FF0A765

Topic A: Introduction to The Properties of Operations

Topic B: Multiplication and Division by 6 and 7

Topic C: Multiplication and Division by 8 and 9

Topic D: Multiplication and Division by Values Greater than 10

Topic E: Two-Step Word Problems and Patterns in Arithmetic

Request a Demo

See all of the features of Fishtank in action and begin the conversation about adoption.

Learn more about Fishtank Learning School Adoption.

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Yes

No

Any other information you would like to provide about your school?

We Handle Materials So You Can Focus on Students

We Handle Materials So You Can Focus on Students

We've got you covered with rigorous, relevant, and adaptable math lesson plans for free