Transformations
Dilations
1. Lesson Title
Dilations
2. Grade Level
Grade 8
3. Subject Area
Math
4. Time allotted for the lesson
1 hour
5. Description of Lesson
In this lesson, the learners will discover dilations. Students will identify and define
dilations as they appear on the coordinate grid. Students will use scale factors to dilate
figures using ordered pairs.
6. State Curriculum Standards
7.8 The student, given a polygon in the coordinate plane, will represent transformations
(reflections, dilations, rotations, and translations) by graphing in the coordinate
plane.
8.8 The student will apply transformations to plane figures
7. Instructional Objectives
a.
Given a figure and transformation graphed on the coordinate plane, the student
will identify the transformation as a dilation.
b. Given a scale factor, students will identify whether the dilation will feature an
enlargement or a reduction.
c. Given a figure graphed on coordinate plane and a scale factor, the student will
create the figure’s image through dilation.
8. Instructional Procedures
a. Anticipatory Set
 Instructor will draw a letter on a not inflated balloon.
 Show the letter to the class and ask the class what will happen to the letter
when the balloon is blown up.
 Blow up the balloon and ask the class if their hypothesis was correct.
 Be sure to explain the letter remained the same shape but only changed in
size.
 Tell the class that a change in size when the shape remains the same is
called a dilation.
b. Lesson
 Work through SmartNotebook lesson on dilations.
 When introducing the definition of dilations (use dilation graphic) give
another example for the class to visualize (dilated eye at a doctor’s office).
 Compare two figures and have the class describe whether the figures
represent dilation. Students must support their answer.
 Introduce scale factor to the class.
 Discuss enlargement (dilation when scale factor is >1) and reduction
(dilation when scale factor is between 0 and 1).
c. Guided Practice
 Complete examples in SmartNotebook lesson.
 Students will need to follow along and record examples in their notebook.
d. Independent Practice
 Have students turn to page 153 of their workbooks.
 Students will independently complete numbers 1-6.
 Students should find the image of each dilation and state whether the
dilation was an enlargement or a reduction.
e. Closure
 Have students explains answers to independent practice examples.
 Review definitions for dilation, scale factor, enlargement, and reduction.
9. Adaptations
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Cloze notes will be provided for students with exceptionalities.
Calculators will be provided when needed.
10.Supplemental Activities
a. Extension
 Have students write a paragraph identifying a dilation in the real world.
They must evidence and definitions to support their answer.
b. Remediation
 Extra examples and problems are provided in the textbook on pages 228230.
 Students who need extra practice may work on dilations using whiteboards
during remediation time.
11.Assessment/Evaluation
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Informal assessment will be taken throughout the lesson by direct observation.
Students who are struggling with the concepts will require assistance from the
instructor. Positive reinforcement will be given to students who show
understanding of material.
Informal assessment will also be taken by examining each student’s work on the
workbook page. Instructor will individually help students who need assistance.
Formal assessment will occur during the Transformation Unit Test.
12.Learner Products
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Students will have recorded various examples in their math notebooks.
Students will have completed workbook page 153.
Students engaging in the extension activity will have created a written description
about a dilation.