Illuminations: Blue Squares and Beyond

This Internet Mathematics Excursion is a pre-activity for E-example 6.3 from the NCTM Principles and Standards for School Mathematics.

This is the first in a sequence of four lessons designed for students to understand ratio, proportion, scale factor, and similarity. This lesson invites students to manipulate two rectangles to create examples of similarity and to study the effects on area ratios. Students sketch similar figures, verify proportionality, and apply these concepts to structures in their world.


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Middle School, Educator

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Illuminations (National Council of Teachers of Mathematics)

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