Guided Lessons

# Shapes to Scale

Teach your students to predict and explain features of scaled regular shapes.

No standards associated with this content.

No standards associated with this content.

No standards associated with this content.

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Students will be able to predict and explain features of shapes that are scaled by factors greater than one.

(5 minutes)
• Show your class two pictures: A model of something, and a picture of the actual item.
• Ask, “Which one is the is the real item?” Allow for student responses.
• Reveal which picture was a model. Note how a model is a version of something, but wouldn’t be very realistic, if it weren’t ‘to scale,’ or have the same features in proportion to the real thing.
• Explain that establishing features in proportion to ScaleMeans to multiply all of the dimensions by the same factor.
(10 minutes)
• Explain that today’s lesson will focus on scaling regular figures (those with equal side lengths) while showing your class a paper cut-out square with 4-inch sides.
• Then, show your students another square with 8-inch sides. Have your class turn and share with a partner how both square compare to one another.
• Allow several students to share their ideas with the whole class. Tell your students that the two squares are ‘to scale.’ The smaller square side length has been scaled by 2 (or multiplied by 2) to create the larger square.
• Allow for students to turn and tell a neighbour how they might explain this idea in their own words.
(5 minutes)
• Hand out copies of the Scaling More Regular Shapes worksheet.
• Preview the entire sheet and review the example with your class. Answer any clarifying questions.
(15 minutes)
• Have your students complete the exercises for the Scaling More Regular Shapes worksheet.

Enrichment:Students can make scaled diagrams of non-regular angular shapes like rectangles, triangles and trapezoids.

Support:Students can start off by practising up-scaling regular shapes by two, moving on to three and four times.

(5 minutes)
• Show your students two shapes labeled A and B. Shape A is scaled by a factor of 5 to create B. Ask students to show fingers that show the scale factor used from shape A to create shape B.
(10 minutes)
• Have students share out their answers, and if others disagree, allow for challenges. Allow for at least two before clarifying correct answers, if necessary.