6 - 9 Grades Social Science
    10 - 12 Grades Social Science
This module is part of a series produced at The Universtiy of Nevada at Reno for the National Numeracy Network under a grant from the Woodrow Wilson Fellowship Foundation through the National Council on Education and the Disciplines. These brief modules are envisioned as a resource for teachers to use in a classroom setting and also for quantitative literacy workshops for teachers. Each module typically contains one or two examples related to "real world" quantitative literacy issues and includes exercises for students. There is also a section "for the instructor" that contains discussions of some of the topics, solutions to the exercises, and resources for further explorations.

 

Consumer Numeracy

Jerry Johnson
University of Nevada, Reno

Quantitative literacy is very important when it comes to being an informed consumer. Quantitatively literate consumers understand how to select the best values and they are less likely to be cheated.

In deciding the best buy on a pizza one needs to be aware that the area of a circle is p r2, which is the same thing as p / 4 = d 2 where d is the diameter. This means that the area is proportional to the square of the radius (or the square of the diameter). Thus, doubling the diameter quadruples the area. Pizza sizes are usually given in terms of their diameters. By the way, p is about 3.14.

In considering the price of carpet, one might need to know how to convert between square feet and square yards. (One square yard is nine square feet.) Other conversions are useful as well, such as between liters and ounces (one liter is about 33.82 ounces).

The mathematics is arithmetic, calculating the area of a rectangle and a circle and, conversion of units of measurement.