As part of the Dragonwings project, students in Ms.
Dunbar's and Mrs. Alejandre's Math 7 classes drew dragons.
Eight dragon drawings were selected to use in a mathematics exercise using the idea of
scale drawings and enlargement to scale.
Objectives:
to facilitate
to apply a scale factor of 1:4
to explain the group's process
Materials:
(for each group of four students)
two Dragon Head pictures
four sheets of large blank paper
four sheets of quarter-inch graph paper
four sheets of one-inch graph paper
four rulers
four pencils
four colored pencils
paper for note-taking
Preparation:
The teacher demonstrates how to enlarge a figure using a scale factor of 1:4.
The students are instructed to outline one square on the quarter inch graph paper
and again one square on the one inch graph paper.
The students are instructed to outline a small triangle on the quarter inch graph paper
and again on the one inch graph paper.
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:
Cut the Dragon Head picture into four sections using the guidelines provided.
Each student in the group is responsible for enlarging to scale one-fourth of the
picture.
The group will use a scale factor of 1:4 [Suggestion: Use the two different sizes of
graph paper to help see the grid.]
Draw your dragon head piece on your large paper.
Write your group's reasoning. Use the lined paper provided.
Evaluation:
Teacher observation during the group activity.
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.