Can You Draw a Larger Dragon?

This activity is aligned to NCTM Standards - Grades 6-8: Measurement, Problem Solving, Communication and Reasoning and Proof and to California Mathematics Standards Grade 7: Measurement and Geometry #1.2, 2.3 and Mathematical Reasoning #1.1, 1.2, 1.3.

As part of the Dragonwings project, students in Ms. Dunbar's and Mrs. Alejandre's Math 7 classes drew dragons. Sixteen dragon drawings were selected to use in a mathematics exercise using the idea of scale drawings and enlargement to scale.

Objectives:

1. to facilitate
   
2. to apply a scale factor of 1:4
   
3. to explain the group's process
   

Materials:

(for each group of four students)

1. two Dragon Head pictures
   
2. four sheets of large blank paper
   
3. four sheets of quarter-inch graph paper
   
4. four sheets of one-inch graph paper
   
5. four rulers
   
6. four pencils
   
7. four colored pencils
   
8. paper for note-taking

Preparation:

1. The teacher demonstrates how to enlarge a figure using a scale factor of 1:4.
   
2. The students are instructed to outline one square on the quarter inch graph paper and again one square on the one inch graph paper.
   
3. The students are instructed to outline a small triangle on the quarter inch graph paper and again on the one inch graph paper.
   
4. To complete the practice session the students are instructed to draw a squiggle on the quarter inch graph paper and again on the one inch graph paper using the grid to make an accurate enlargement.
   

Tasks:

1. Cut the Dragon Head picture into four sections using the guidelines provided.
   
2. Each student in the group is responsible for enlarging to scale one-fourth of the picture.
   
3. The group will use a scale factor of 1:4 [Suggestion: Use the two different sizes of graph paper to help see the grid.]
4. Draw your dragon head piece on your large paper.
   
5. Write your group's reasoning. Use the lined paper provided.
   

Evaluation:

1. Teacher observation during the group activity.
2. The four large sheets will be combined to show one large dragon head. If they fit and look like an accurate enlargement, the task has been accomplished.

Dragon Head Pictures 1998-99:

Dragon Head One Dragon Head Two Dragon Head Three Dragon Head Four Dragon Head Five Dragon Head Six Dragon Head Seven Dragon Head Eight

Dragon Head Nine Dragon Head Ten Dragon Head Eleven Dragon Head Twelve Dragon Head Thirteen Dragon Head Fourteen Dragon Head Fifteen Dragon Head Sixteen

Dragon Head Pictures 1997-98:

Suggestion: Print in color.

Dragon Head One Dragon Head Two Dragon Head Three Dragon Head Four Dragon Head Five Dragon Head Six Dragon Head Eight

Photographs of Student Activity:

Photos of 1997-98 students working on the activity.

Photos of 1997-98 students holding their finished group activity.