**ERIC Number:**EJ920855

**Record Type:**Journal

**Publication Date:**2011-Apr

**Pages:**6

**Abstractor:**ERIC

**Reference Count:**7

**ISBN:**N/A

**ISSN:**ISSN-0025-5769

Flower Power: Sunflowers as a Model for Logistic Growth

Fernandez, Eileen; Geist, Kristi A.

Mathematics Teacher, v104 n8 p580-585 Apr 2011

Logistic growth displays an interesting pattern: It starts fast, exhibiting the rapid growth characteristic of exponential models. As time passes, it slows in response to constraints such as limited resources or reallocation of energy. The growth continues to slow until it reaches a limit, called capacity. When the growth describes a population, "capacity" is defined as "the maximum population that the environment is capable of sustaining in the long run." In this article, the authors describe an approach to studying logistic growth that is accessible to students with a knowledge of spreadsheets. They begin by building on students' knowledge of linear functions to represent the logistic growth rate algebraically. Then they use a spreadsheet design by Neuwirth and Arganbright (2004) to model logistic growth and apply the design in studying the average height of a field of sunflowers. They chose to study sunflowers because sunflowers grow to a tall-enough height--8 feet--in a manageable period of time, and thus their growth can be displayed in a manageable number of spreadsheet rows. Finally, the authors provide a related activity for students with calculus backgrounds, thus connecting their work to that appearing in calculus textbooks. (Contains 7 figures.)

Descriptors: Textbooks, Calculus, Mathematics Instruction, Mathematical Concepts, Spreadsheets, Plants (Botany), Algebra, Teaching Methods, Population Growth, Computer Uses in Education, Equations (Mathematics), Secondary School Mathematics, High Schools

National Council of Teachers of Mathematics. 1906 Association Drive, Reston, VA 20191-1502. Tel: 800-235-7566; Tel: 703-620-3702; Fax: 703-476-2970; e-mail: orders@nctm.org; Web site: http://www.nctm.org/publications/

**Publication Type:**Journal Articles; Reports - Descriptive

**Education Level:**High Schools

**Audience:**Teachers

**Language:**English

**Sponsor:**N/A

**Authoring Institution:**N/A