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ERIC Number: EJ926574
Record Type: Journal
Publication Date: 2011-May
Pages: 6
Abstractor: ERIC
Reference Count: 5
ISSN: ISSN-1072-0839
Proportional Reasoning with a Pyramid
Mamolo, Ami; Sinclair, Margaret; Whiteley, Walter J.
Mathematics Teaching in the Middle School, v16 n9 p544-549 May 2011
Proportional reasoning pops up in math class in a variety of places, such as while making scaled drawings; finding equivalent fractions; converting units of measurement; comparing speeds, prices, and rates; and comparing lengths, areas, and volume. Students need to be exposed to a variety of representations to develop a sound understanding of this concept, particularly in the middle grades. This article describes an activity designed to foster learners' ability to use visualization, spatial reasoning, and geometric modeling to solve problems. Filling the Pyramid is a hands-on investigation that incorporates dynamic geometry software. It explores three-dimensional models and two-dimensional geometric representations to illustrate properties of proportion and dilation. The steps for creating the sketches in this article, including snapshots of the screen, are appended to the online version of this article at (Contains 4 figures.)
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:; Web site:
Publication Type: Guides - Classroom - Teacher; Journal Articles; Reports - Descriptive
Education Level: Middle Schools
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A