ABSTRACT
Th e Activity Focus: Ms. Levy uses a scale for proportion to introduce students to the concept of percent and its use in problem solving.
Ms. Levy distributed the grid as she spoke to the class (see Figure 14.1). “Today we will spend the fi rst part of the class constructing a problem solving grid and then we will solve some problems using it.” She then placed an acetate copy on the overhead and continued. “You have two columns. Th e one on the right is calibrated by 5 from 0 to 100. Th e left column has a 0 opposite the 0 in the right column. At the top of the left column opposite the 100, I want you to write 800. What we are now going to do is fi ll in the left column using simple arithmetic and its relation to the right column.”
