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đź“ŠLesson 3.3 Outline- Arrays (One-Digit X Two-Digit) (For Teacher- Do Not Publish)

Lesson 3.3

For full lesson outline please see  Advantage Math Lesson 3.3.

Standards:

4.NBT.5- Use strategies based on place value and the properties of operations to multiply a whole number of up to four digits by a one-digit whole number, and multiply two, two-digit numbers.

Objectives:

Math Objective: Students will be able to represent multiplication using an area model and draw the representation using the box-line-dot method

Language Objective: Students will be able to discuss with a partner how to model a multiplication problem with an array.

Vertical Alignment:

3.OA.7.B- Know from memory all products of two one-digit numbers 

4.NBT.5- Use strategies based on place value and the properties of operations to multiply a whole number of up to four digits by a one-digit whole number, and multiply two, two-digit numbers.

5.NBT.5- Fluently multiply multi-digit whole numbers using the standard algorithm

Common Misconceptions:

None noted in Advantage Math Lesson 3.3 

Lesson Outline:

🚀Launch (in class or remote)

Insert video of how to use an Array Bar Map. This video should not show them how to solve using an Array Bar Map but it should show the background knowledge that a student would need to have in order to solve what is asked of them.

  • Students are asked to use an Array Bar Map. They are asked to solve a simple problem, 3 X 5.
    • Questions you could ask:
      • How could using an Array Bar Map be helpful?
    •  Vocabulary words: Area, Area Model, Array

🤔Explore (in class or remote)

  • Students should have an idea of how to use an Array Bar Map. With that understanding, the focus is on how to solve a multiplication problem. They will compare the base-ten. numeral version to the version where numbers are represented in Base Ten Blocks. As they work through the Explore assignment, they will look at the setup when looking at a one-digit by two-digit multiplication problem and also how to find the answer. Students are finally asked to solve an equation on their own. 
    • Questions you could ask:
      • When looking at the Array Bar Map, how do you determine what the answer is?

đź’¬Discuss (in class or remote)

  • Questions to use in your discussion:

    • How has decomposing numbers helped you when solving multiplication problems?

    • When multiplying numbers, when do you think you would need to decide if a number is uncomfortable for you to try to multiply? Would decomposing that number or those types of numbers be a helpful strategy?

Additional Resources:

  • “Number Pieces” app by Clarity Innovations. This app allows students to manipulate base-ten blocks. Available in the App Store on iPads.
  • Differentiation (in class or remote)
    • Challenge: Ask students to use the commutative property to switch the factors on the charts. Compare the drawings and models (The rods will be vertical instead of horizontal, but the quantity and product are the same).
      • Ways to make remote:
      • Students can do this challenge on their own and submit their work and thoughts. 
    • Struggling : Have students make smaller arrays with one-digit x one digit numbers before adding two-digit numbers. Progress to single-digit numbers multiplied by multiples of 10, e.g., 4 Ă— 30. This gives students the opportunity to use just the tens rods. Continue to use the manipulatives and transition to the pictorial “box-line-dot” method. 
      • Ways to make remote:
      • Have students join you in an online meeting format (Zoom or Teams) and do the exact same activity. They might not have the place value disks, but you can show them yours to discuss.

 

  • Lesson Extension (in class):
    •  Have students create a matching game of equations and pictures of Array Bar Maps. Other students could match the equation to the picture.