Which Operations? (Part 1)

This Instructional Activity is a part of the Lesson 3, Unit 1, Grade 7. The purpose of this activity is to contrasts the effects of multiplying side lengths versus adding to side lengths when creating copies of a polygon. To find the corresponding side lengths on a scaled copy, the side lengths of a figure are all multiplied (or divided) by the same number. However, students often mistakenly think that adding or subtracting the same number to all the side lengths will also create a scaled copy.