When I first started teaching scale factor to 7th graders, I wanted to pull my hair out because I really couldn't find this skill in our textbooks. This year I decided I was going to just create my own. This lesson has 66 slides and can be taught over a week. You could generate some homework worksheets from the slides. It explains this hard concept in grave detail. If you want to print and teach, this is your product. I used it in my own class; so, it is classroom approved.