Judging size with proportional reasoning is shown using lengths of the show host transposed on a dinosaur and transposing an artist's pencil on a picture. The meaning of scale modeling is show with model trains, model cars, and a mural painting on a bus. One artist who used grids to stretch his work onto a large field and another artist who shrinks his pictures into miniature paintings describe their procedures. An architect discusses her work creating scale models. The purpose of these lessons is to help students visualize and conceptualize percents and to use proportions for solving comparisons expressed in percents.
Percents have the special trait of always comparing to one hundred.
In the jewelry business, proportions and percents are used to describe the purity of gold and the cutting of gems. In the ice cream business, percents are used to describe the ingredient percents and sales. Percents are discussed while explaining the preparation and sales at a potato chip factory. Back to Proportional Reasoning .