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What's My Change

Lesson Plan

What's My Change

Grade Levels

10th Grade, 11th Grade, 12th Grade, 9th Grade

Course, Subject

Algebra I, Mathematics

Vocabulary

Perimeter – the measure of the distance around the outside of a two-dimensional object

Area – the number of square units inside a two-dimensional figure

 

Objectives

The students will be able to identify how the change in the value of one variable affects the other variables in the measurement of area and perimeter.

Students will:

  • compute area and perimeter given length and height and scale of one rectangle
  • compute surface area and perimeter and determine the ratio of surface areas and perimeter between the object and the model
  • learn through inquiry, that if the dimensions of an object are multiplied by a scale factor n, then the surface area is multiplied by n2
  • Lesson Essential Question(s)

    How does changing the length of one of the sides of a rectangle change the perimeter of the rectangle?

    How does changing the length of one of the sides of a rectangle change the area of the rectangle?

    Duration

    1 class period

    Materials

    Notecards

    A computer per student or one computer per group of two

    Website for Scale Factor Activity:  http://illuminations.nctm.org/ActivityDetail.aspx?ID=176

    Student worksheet Student worksheet 3.DOC

    Suggested Instructional Strategies

    WHERETO

    W

    =

    The opening activity of reviewing how to find the perimeter and area of basic 2-dimensional shapes and the leading question of what will happen if one of the dimensions is multiplied by a certain number will lead the student to where and why we are doing this activity.  Students will be told that they will be evaluated by the completion of the worksheet.

    H

    =

    The use of technology and the interactive website applets will generate students’ interest.  The use of inquiry will garner student interest and engagement.  The use of real world data will provide appropriate application and show how this knowledge can be used in everyday situations.

    E

    =

    The worksheet walks the students through the discovery of the mathematic principles behind this lesson.  The interactive website promotes student success in completing the assignment. 

    R

    =

    Questions throughout the activity will promote the student thinking the application of the mathematical concepts in this lesson.

    E

    =

    Students will complete the worksheet and revisit this concept in the follow up questions asked at the end of class.

    T

    =

    By design, this lesson uses kinesthetic, visual, auditory, and hands-on activities.  Through teacher monitoring, ongoing reteaching and remediation will occur.  The use of student partners may assist struggling students in addition to remediation activities and extra practice to reinforce the concepts taught.

    O

    =

    The teacher will first model the activity by guiding the students through the first example.  Students then will work independently on the remaining examples.  Students will develop self-knowledge through the use of this inquiry based instruction.

    Instructional Procedures

    The teacher will begin the class by reviewing the concepts of perimeter and area of basic 2-dimensional shapes.  The teacher will provide each student with a note-card.  On the front of the note-card the students will record the word "perimeter" and on the back of the note-card the students will record the word "area".  The teacher will state examples of scenarios that require the students to determine if perimeter or area is needed to complete a task.  For example,  "If you want to wallpaper one wall of your bedroom would you need to find the area or perimeter?" The students will use their note-cards to respond.  The teacher will use student responses to gauge student mastery and adapt instruction as necessary.  The teacher will also review the perimeter and area formulas.  The students will be reminded that these formulas are available on the PSSA formula sheet. 

    The teacher will inform the class that they are going on a search to see if we can determine what will happen to the perimeter and area of a 2-dimensional shape if we change one of the dimensions by a certain factor.

    The teacher will model how to access and use the Scale Factor interactive http://illuminations.nctm.org/ActivityDetail.aspx?ID=176 – showing how to change the dimension of the original boxes width and height (the red handles) and how to change the scale factor (the slider at the bottom of the screen).  

    The student will be directed to then log on to the computer either individually or in groups of two.  Teacher will distribute Student Worksheet 3.  Teacher will model the first example using Think Aloud strategies for problem-solving.  Students will then independently complete the rest of the items while the teacher circulates to monitor progress and provide correction as necessary.

    Prior the end of the period, the teacher will review the student answers as a group activity to ensure understanding and mastery of the lesson.

    As a follow-up assignment, the teacher may ask the class what they think will happen to the perimeter and the area of a circle if the radius is changed by a factor of 3.

    Formative Assessment

    Response cards will be used to assess student knowledge regarding area and perimeter and its application in different scenarios at the beginning of the lesson.  Additionally, teacher monitoring will provide reteaching and remediation as necessary.  These formative assessments will provide the teacher with the opportunity to make adjustments in the instruction as needed.

    Related Materials & Resources

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    Date Published

    March 29, 2010
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