It's All About Scale

Designed by:   David K. Blackwell, Gibbes Middle School  

GRADE LEVEL: 6th         SUBJECT(S):  Math

1) CORE CURRICULUM OBJECTIVE(S): Use a given scale to interpret a scale drawing and construct a scale model (e. g., maps, globes, or blueprints). (6ME1-3)

Use ratio and proportion in everyday situations. (6NR8-2)

RESTATEMENT:

The student will construct a scale model from a given scale.

The student will find the ratio between two everyday objects - EXAMPLE: Matchbox car and a real car.

2) OVERVIEW:   Children all over the world love to play with toys. In America toys are available everywhere - from the Golden Arches of McDonald's to the local Toys 'R' Us. Children's toys are frequently small-scale representations of their real-world counterparts. Activities will actively involve the students and allow them to study scale, proportions, and ratios through the connection of these toys to the real world. Students will work in cooperative groups to measure toys and to complete tables for known-scale and unknown-scale toys. They will compute the toys' "life-sized" counterparts' measurements, and draw these outline by using large sheets of bulletin board paper taped together or by drawing with chalk on a concrete area outside.

3) FOCUS/ESSENTIAL QUESTION(S):

1. If you went to a hobby store and saw a toy ship with1:94 stamped on the box, what would these numbers mean to you?

2. Is a Matchbox car or Hot Wheel car a good scale model of a car? Why or why not?

3. If you have a scale of 1 inch = 2 feet, would that be a reasonable scale to complete a scale drawing of your bedroom or to do a scale model of a school bus?

4. What occupations would need to know about scale drawings and scale models?

4) TIME FRAME:    Two class periods (45 or 50 minutes each)

You may need an extra class period depending on the ability levels of your students.

5)  RESOURCES:

Glencoe Course 1      (Optional) 

Computers with Internet access

Internet sites or On-line reference tools such as Encarta

Bulletin Board Paper

Pencils

Markers    

Large sticks of chalk

Metric and customary measurement tools (calipers, rulers, tape measures, trundle

wheels)    

Scale models of toys [Matchbox Cars, Hot Wheels, Barbie and Ken dolls, GI Joe, or other toys that your students bring in for extra credit

Copies of Table I, Table II, Table III, Table IV (See Attachments.)

Transparencies

Shoeboxes or large zip-lock bags

Sticky Notes

6) ASSESSMENT: The following rubric will be used to assess the student's understanding of scale. The points can be converted to assign a grade by using the appropriate grading scale.

ASSESSMENT RUBRIC FOR IT'S ABOUT SCALE

7) INSTRUCTIONAL ACTIVITIES:

A day or two before beginning the lesson, have students bring in small toys such as Matchbox cars, Hot Wheels, small figures & dolls, and other toys. Have them bring a shoebox to place their toys in during the activities. Put their names on the boxes. Tell them they will get extra credit points for "loaning their toys."

DAY ONE

1. Begin Day One activities by asking the focus questions. Discuss responses, but don't spend more than five minutes on the questions.

2. Explain the day's objectives and goals.

3. Have students examine the toys they have brought in earlier for any words or numbers and write these on the overhead transparency TABLE I. Each student should do one toy.

4. Discuss these numbers.

5. Have volunteers measure one model car using a metric caliper or tape measure to find its length, width, and height. (Customary measurement tools may be used instead.)

6. Have students estimate the number of times the model car's measurement would have to be increased to represent a real car's size. They can use calculators and should write these measurements down in their journals (if you have them keep one). Convert these numbers to meters to find the real car's measurements.

7. Divide the students into cooperative groups by randomly assigning numbers or by letting the students choose their groups' members. Assign the following roles:

* Calculator operator - Responsible for computing the real object's measurement

* Graphic artist - Draws top, side, rear, and front views to scale on centimeter graph paper

* Metric measurer - Responsible for using meter sticks, trundle wheels,  tape measures, and/or calipers

* Quality-control manager - Records information and watches the time.

8.  Groups will choose eight toys from the collection.

9. Groups will measure these toys and complete Table II and Table III.

10. Using online reference sources (Encarta, World Book, Britannica), the groups will find real-life measurements for their groups' eight toys.

11. Groups will choose one toy. Using the trundle wheels or tape measures, bulletin board paper and markers, the groups will draw their chosen toys life-sized counterparts. They may also use chalk and draw the objects outside on concrete.

12. After completing the drawings, have students respond in writing to the following:

a. Describe the relationship of scale as it relates to the day's activities.

b. If you have a model ship marked 1:23, what does this mean to you.

DAY TWO

1. Review the previous day's activities.

2. Randomly assign pairs. Have each pair measure the height of their partner using a customary or metric unit and record it on a sticky note.

3. Have the students place their sticky notes on a graph you have prepared earlier.

(You can use the following model as a guide to the graph.)

4. Have a student volunteer to add all of the heights for boys in the rooms.

Have the volunteer divide this sum by the number of boys to find the average height of a sixth grade boy. (You should decide whether the students use the metric or customary system of measurement.)

5. Repeat step 4 for the girls.

6. Write these measurements on TABLE IV; an overhead and student copies will be needed of this table.

7. Hold up male and female dolls from the collection of toys. (GI Joe, Barbie, Ken, etc.) Tell the students that they are going to figure out the number relationship for the dolls and the average sixth grade boy and girl.

8. Have volunteers measure the dolls with the same measurement device to get their height. Write these measurements on TABLE IV.

9. Have the students write the numbers on their copy of TABLE IV. Ask them to estimate how many Barbies it would take to equal the average sixth grade girl and write this on their table. Do the same for the GI Joe or Ken doll and the average sixth grade boy? Have them to record this information on TABLE IV.

10. Using round-robin, let each student share their estimates for both dolls. Have a two volunteers write these numbers down and add the Barbie estimates together. Divide this number by the number of Barbie responses to find this "estimate average", and record this number on TABLE IV.  Do the same for the Ken or GI Joe doll.

11. Ask the students to find the number relationship between the Barbie and Ken dolls to the average sixth grade girl and boy by dividing the dolls heights into the averages of the sixth grade girl and boy.

12. For closure have the students to respond to the question on TABLE IV. Share these with their classmates.

TABLE I OVERHEAD TRANSPARENCY
TOY'S NAME	COUNTRY OF ORIGIN	PART NUMBERS	COPYRIGHT YEAR(S)	WHO MADE THE TOY	"WEIRD NUMBERS"

TABLE IV