Women and Minorities in Mathematics:

Incorporating their Mathematical Achievements into School Classrooms

Dr. Sarah J. Greenwald and Dr. Andrew Nestler

Research has shown that incorporating the mathematical achievements of women and minorities into school classrooms is beneficial to all students. Some conclusions:

"Although evolved to attract men of color, women, and others underrepresented in the pool of scientists, these techniques have been shown to be as successful -- or more so – for white males." (Davis & Rosser, 1996)

"Not only are more women and people of color likely to become scientists, but also more men may choose careers in science, since these improved methods have been shown to also be attractive to white males." (Rosser, 1990)

"Males who perceived mathematics teachers as treating males the same as females tended to take more mathematics." (Armstrong, 1985)

There are many references on activities incorporating multiculturalism for the classroom (e.g., Campbell & Campbell-Wright, 1995; Edwards, 1999; Karp, 1998; Ortiz-Franco, 1999; Strutchens, 2000; Trentacosta, 1997). Yet, except for a few sources such as Johnson (1999), Lumpkin (1997), Lumplin & Strong (1995), Parker (1995), and Perl (1978), sources that discuss the mathematical achievements of women and minorities do not include activities for inclusion in the classroom. This is unfortunate since all students benefit from this inclusion, as "the result is that students will see mathematics as a discipline that transcends culture, time, and gender, and as a discipline for everyone, everywhere." (Johnson, 1999, p. xi)

This is the inaugural column of a semi-annual "Women and Minorities in Mathematics: Incorporating their Mathematical Achievements into School Classrooms" series. This article explores the inclusion of the research of Carolyn Gordon and Kate Okikiolu on hearing the shape of a drum into school classrooms. This is a great topic since it is fun and easy to make drums of different shapes and listen to them in class. It is also an entertaining way to demonstrate to students that there is not always just one conclusion that can be reached from a complete set of measurements. Sample classroom activity sheets can be found online (Greenwald, 2000).

Carolyn Gordon is very well known for her research, and she presents it at conferences all over the world. She has received numerous grants and awards, such as the American Mathematical Society Centennial Fellowship. She is currently the Cheney Professor of Mathematics at Dartmouth College.

Much of what scientists know about our world comes from indirect observations. For example, X-rays, CAT scans, and other medical imaging techniques are indirect ways of seeing inside the body. Mathematicians are also concerned with indirect ways of observing the world around them. In 1966, the Polish-American mathematician Mark Kac asked if one can always hear the shape of a drum. The problem challenged researchers for nearly three decades. Finally, in the spring of 1991, Gordon and her fellow researchers came up with the answer: No. They found two drums that have different shapes, yet sound exactly the same when they are played (Cipra, 1997a).

Kate Okikiolu is also well known for working on hearing the shape of a drum. She is the first person of African descent to have won one of the most prestigious awards for young mathematics researchers, a Sloan Research Fellowship. She is a professor of mathematics at the University of California at San Diego. Okikiolu explains (McDuff, Janks, Phillips, Phillips, & Snyder, n.d.) her research: "The sound of a drum changes as its shape changes. In fact, listening to the drum very carefully tells me how to change its shape to make it sound like a round drum and when it sounds like a round drum, it is indeed round!" Okikiolu has "developed a mathematical procedure called 'moving to the music' that links sounds to shapes… You're blindfolded, listening to drum music, and someone asks you to draw the drum." (Davis Kivelson, 1999) While Carolyn Gordon's mathematics tells us that we cannot always distinguish between drums of different shapes, Kate Okikiolu's mathematics succeeds in distinguishing the shapes of certain types of drums.

Now we offer activities designed to introduce ideas related to the research of Carolyn Gordon and Kate Okikiolu to students. Classroom worksheets based on these activities can be found online (Greenwald, 2000). Slight modifications make these worksheets appropriate for use at a variety of grade levels.

Explain to students that one can hear the size of a drum, and ask the students to bring drums into the classroom. Ask the students to close their eyes and listen to the different drums being played, and ask them to draw the shape of the drums they hear. See if they can guess that larger drums have lower pitches. Wrap a string around the outside of the drums to compare perimeters. Fit small, square tiles onto the drum heads to compare areas. Use a ruler and mathematical formulas to find the perimeter and area of each drum.

A two-piece band is a union of two drums. Given a known example (Cipra, 1997b) of two distinct two-piece bands that produce the same sounds, students can verify that each band has the same total perimeter and area. They can attempt to discover other such examples as well, first with restrictions, such as using only rectangles. Using solid materials, they can build physical drums to form their own two-piece bands.

Since one can hear the area and perimeter of a drum, if students were looking for two soundalike drums, then these drums would have to have the same area and the same perimeter. The following represent some of the many possible student explorations of perimeter and area of circles and polygons.

Students can explore why two circles of different sizes can never have the same area or the same perimeter. Using algebra to solve two equations with two unknowns, they can show that a circle and a square can never have both the same area and perimeter. The solution yields a radius and side both of length zero, so this could lead to a discussion that a zero radius or side length means that the figure is a point.

To show that a circle and a rectangle can never have both the same area and perimeter, students can solve equations relating the area and perimeter for the radius of the circle, r. Let x and y be the lengths of the sides of the rectangle. One obtains the equation after equating the radius conditions and then simplifying the resulting equation. Students can use a computer algebra program such as Maple to algebraically solve this equation in order to see that there are no non-trivial solutions. In addition, for x and y larger than 0, they can create a three-dimensional plot of the surfaces on each side of the above equation. They can then rotate the plot and examine different views of the surfaces in order to see that they never intersect.

Since Carolyn Gordon was looking for soundalike drums, she had to find two drums with the same area and perimeter that also sounded the same when they were played. Introduce students to the pictures of the drums discovered by Gordon and Webb (Figure 1; see also Peterson, 1997b, 1997c). Explain that Carolyn Gordon proved that her drums sounded the same without actually testing them out in real life and explain why a mathematical proof does not need to be constructive. Since the students will be worried about this, explain that some physicists created the drums and tested them in real life. They found that the drums sounded nearly the same with an error attributed to the experimental procedures (Peterson, 1997a).

Have students cut along the boundaries of the soundalike drums (Peterson, 1997b, 1997c). Students can cut one of the drums into pieces and try to fit the pieces onto the other drum. They will discover that the drums do not have the same area, which contradicts the fact that they must in order to sound the same. Students can resolve the apparent conflict by investigating the accuracy of the models. Students can identify which drum resembles the drum that Carolyn is holding in Figure 1. Have them fold this drum in order to make five pieces so that two are crosses of the same size, and the other three are halves of a cross (split along the diagonal of the square in the middle of a cross). Student can cut along their folds and then try to fit the pieces onto the other drum. Once they identify which piece does not fit properly, they can compare an uncut version of the drum to Carolyn's drum in Figure 1 in order to see that this piece was not drawn to scale. Explain the dangers of relying on models by discussing some of the difficulties involved in creating physical models representing abstract figures with precisely determined sides. Challenge the students to create a perfect model of Carolyn's drum that is drawn to the same scale as the other drum.

While many of the ideas that we describe here can be nicely visualized in a dynamic geometry software program such as Geometer's Sketchpad, problems arise with accuracy. For example, for the kettledrum activity, students can use Sketchpad to draw regular polygon drumheads (see Greenwald (2000) for scripts and examples). Then, students can use the Measure command to have the program calculate the area and perimeter of each figure. By clicking at the appropriate place and dragging, they can rescale the figures so that they each have area one. They will have trouble succeeding due to the discrete nature of such software and may be tempted to say that this is impossible to achieve. In fact, one may wish to start these activities with Sketchpad for motivation, by asking if it is possible to construct regular polygons of equal areas, in order to highlight the dangers of relying only on visualization software. Aside from this accuracy issue, Sketchpad beautifully illustrates the relationships between the number of sides, the perimeter and the area of regular polygons and circles.

We hope that these activities and references are informative and enjoyable, and would be happy to mail copies of the classroom activity sheets to those without web access. We welcome any feedback regarding the use of these or similar activities in the classroom.

Armstrong, Jane M. (1985). "National assessment of women in mathematics." In Susan F. Chipman, Lorelei R. Brush, & Donna M. Wilson (Eds.), Women and mathematics: Balancing the equation. Hillsdale, NJ: Lawrence Erlbaum.

Campbell, Mary Ann, & Campbell-Wright, Randall. (1995). "Towards a feminist algebra." In Sue Rosser. (Ed.), Teaching the majority: Breaking the gender barrier in science, mathematics and engineering. New York: Teachers College Press.

Davis, Cinda-Sue, & Rosser, Sue. (1996). "Program and curricular interventions." In Cinda-Sue Davis. et al. (Eds.), The equity equation: Fostering the advancement of women in the sciences, mathematics, and engineering. San Francisco: Jossey-Bass Publishers.

Edwards, Carol. (1999). Changing the faces of mathematics: Perspectives on Asian Americans and Pacific Islanders. Reston, VA: National Council of Teachers of Mathematics.

Johnson, Art. (1999). Famous problems and their mathematicians. Englewood, CO: Teacher Ideas Press.

Karp, Karen, et al. (1998). Feisty females: Inspiring girls to think mathematically. Portsmouth, NH: Heinemann.

Lumpkin, Beatrice. (1997). Geometry activities from many cultures. Portland, ME: J. Weston Walch.

Lumpkin, Beatrice, & Strong, Dorothy. (1995). Multicultural science and math connections: Middle school projects and activities. Portland, ME: J. Weston Walch.

Ortiz-Franco, Luis. (1999). Changing the faces of mathematics: Perspectives on Latinos. Reston, VA: National Council of Teachers of Mathematics.

Parker, Marla. (1995) She does math! Real-life problems from women in the job. Washington, DC: Mathematical Association of America.

Perl, Teri. (1978) Math Equals: Biographies of Women Mathematicians + Related Activities Menlo Park, CA: Addison-Wesley Publishing Company.

Rosser, Sue. (1990). Female-friendly science: Applying women's studies methods and theories to attract students. New York: Pergamon Press.

Strutchens, Marilyn. (2000) Changing the faces of mathematics: Perspectives on African Americans. Reston, VA: National Council of Teachers of Mathematics.

Trentacosta, Janet. (1997) Multicultural and gender equity in the mathematics classroom: The gift of diversity. Reston, VA National Council of Teachers of Mathematics.

Davis Kivelson, Pamela. (1999). Dancing to the music in higher dimensions [Poster]. University of California at Los Angeles: SciArt Project (May not be reproduced without permission; see also Figure 2.)