Lesson Plan Scale Factor Course: Math 9 Resource(s): Nelson, Web sites
Big Mathematical Idea/Concept: Scale factor, ratio and proportion
Learning Outcome(s)(Target)
SS9.3. Demonstrate understanding of similarity of 2-D shapes. [C, CN, PS, R, V] / Indicators that will be met
g. Identify and describe situations relevant to self, family, or community that involve scale diagrams and explain the meaning of the scale factor involved.
i. Draw a diagram to scale that represents an enlargement or reduction of a given 2-D shape and explain the strategies used.
j. Explain how to determine the scale factor for a given 2-D shape and an enlargement or reduction of the shape.
l. Solve situational questions involving scale diagrams and scale factors.
Learning Goal: Students will be able to: Determine a scale factor and produce an enlarged figure by applying that scale factor to several measurements.
Assessment: Formative (How will you check for understanding?) Summative: What will your assessment look like for this outcome?)
The finished life size drawing and computations shown.
Mathematical processes that will be met/employed (CM,CN,ME,PS,T,R,V)
All of them! / Differentiation: Groups are stratified, allowing for peer tutoring and selecting tasks
Extensions/enrichment: This is natural extension because it will lead to a discussion of society and health.
Technology Required?
Projector, you tube video
Calculators. Doc camera to demonstrate / Teaching materials: Handouts, manipulatives? One Barbie or Ken per group, measuring tape, roll paper,
Lesson Outline:
Prerequisite Knowledge: Understood or requires review (preassessment)? Advance planner?
They already know how to find scale factor, enlargement, reduction. So they will simply find scale factor based on arm length. Lisa will review with them how to do this.
Motivational Set: We always think Barbie is a reduced beautiful female. Matel has been criticized about the way Barbie looks. Why do you think that is? Have you ever wondered what Barbie would look like if she were life size? Would she be realistic? How about Ken?
Development (including examples) (attach lesson notes if necessary. Consider student interaction before, during, and after)
Time? Intro and instructions: 5 minutes.
Lisa prepared a handout. Students will use arm length as a reference point. **Question: Where did the University student (in the video) start for her scale factor??
After determining the scale factor, groups will work through the handout, enlarging each measurement. We are working with a 3D object but using 2D measurements, with calipers. One group will do frontal view, other group side view, there are two Barbie groups and two ken groups.
Grouping: Lisa has prepared groups of varying abilities (stratified groups). Cindy will give a discussion of group work:
1. Why do we do group work?
2. Focus on the learning, with support
3. Importance of dialogue to solidify our learning
4. Respectful group interaction
5. Group roles: a) materials manager, b) one or two monitors, c) reporter
Materials manager will obtain a metre stick and a caliper. Designate group assignements (Barbie/Ken/front/side)
A long sheet of paper, (possibly two)
Calculator
***Number of decimal places is a matter of choice.
Calipers are in inches, or cm, or some of each. Mearurements must be in cm.
Actions: (Model, group, pair, individual guided practice. Opportunities to respond?)
Model caliper use and view of Barbie
Summary: (exit slip? ) Be sure to stop with 12 minutes left in class. We need to hear from each group:
How realistic are your measurements? What surprised you? What portion is most distorted?
Do you know how to find and apply scale factor? Was it useful working in a group this way?
Discussion (closing): Why has Matel faced criticism re: body image? Is this dangerous? Is body image an issue in men?
Watch video
http://www.drrobynsilverman.com/body-image/the-truth-about-barbie-galia-slayens-life-size-barbie-on-the-today-show/
http://www.nbcnews.com/id/15160230/ns/health-mens_health/t/guys-have-body-issues-too/
Assignment/homework There is no homework, assessment is their work, their large image with calculations shown.
Reflection? Half way through reflection:
1. The lesson will take two classes
2. We need to review scale factor and how to find it, and clarify what is the “original” measure.
3. Group Norms should be recorded as they are discussed, and revisited
4. Reinforce importance of units! If they are measuring in inches they need to convert to cm.
5. Have them do all the doll measurements first , because they could then save time by converting them all, and that work could be caught up at home
6. have the prototype poster layout ready ahead of time.
The small group arrangement did allow us to get around to each group and clear up misconceptions, help with understanding, and monitor group interaction.
7. Add total height to handout.
8. We should have started with a learning target: I can: calculate a scale factor and use that scale factor to enlarge an image
Lisa has decided to ask for a journal entry tomorrow based on this assignment.
Notes:
Planning Guide:
Consider:
· Lesson goals
· Lesson plan an design
· Students’ relevant prior knowledge.
· Relationship between the nature of the task and the activity on one hand and the lesson goals on the other hand.
· Strategies for students to make public their thinking an dunderstanding.
· Evidence of students’ understanding and learning
· Students’ difficulties, confusions and misconceptions
· Ways to encourage collaboration in an atmosphere of mutual respect
· Strategies to foster relevant student discussion
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