Understanding Multiplication Using Dynamic Sketches of an Area Model

  • 6.1 Understanding Multiplication Using Dynamic Sketches of an Area Model

    Grade: 6th to 8th

    Students are encouraged to build conceptual reasoning for multiplying decimals by manipulating an area model.

    Activity

    Instructions

    ·       Multiply decimals up to 7.0 x 7.0 by dragging the white slides

    ·       Press calculate to determine the area or determine the area on your own and then check to see if your solution is correct

    ·       Press replay to revisit the solution path

    ·       You can also alter the area by clicking on the tab that is located on the upper right hand corner of the rectangle



    Exploration

    1.     Create a rectangle with a fixed width of 3 and a height of your choice. What do you notice?

    2.     Represent the height of the rectangle using the variable y. Determine an expression that can be used to find the area of any rectangle with a width of 3.

    3.     Change the value of y so that y>1 and y<1. How do these area models compare?

    4.    How can you determine the area of a rectangle when the width and the height are both decimals numbers?

    Solution Guide



    Objectives and Standards

    NCTM Standards and Expectations
    • Number and Operations
    • 6-8
    • Number and Operations