ERIC Number: EJ1116673
Record Type: Journal
Publication Date: 2016-Oct
Nifty Nines and Repeating Decimals
Brown, Scott A.
Mathematics Teaching in the Middle School, v22 n3 p178-181 Oct 2016
The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how do prealgebra students in the middle grades convert repeating decimals to fractions without using the age-old algebraic process (multiplying and finding the difference of two "stacked" equations) or without applying the precalculus approach of treating repeating decimal digits as an infinite geometric series? The author has created a repeating decimal-to-fraction conversion activity to integrate inductive and deductive methods in a nonalgebraic context that actually leads to a formal, but less conventional, algebraic justification of the conversion process. He calls the activity Nifty Nines. The Nifty Nines activity, which is presented in this article, engages students in processes that are central to the development of concept and operation understandings involving rational numbers.
Descriptors: Mathematics Instruction, Secondary School Mathematics, Algebra, Fractions, Equations (Mathematics), Arithmetic, Learning Activities
National Council of Teachers of Mathematics. 1906 Association Drive, Reston, VA 20191. Tel: 800-235-7566; Tel: 703-620-9840; Fax: 703-476-2570; e-mail: NCTM@nctm.org; Web site: http://www.nctm.org/publications/mathematics-teaching-in-the-middle-school/
Publication Type: Journal Articles; Reports - Descriptive; Guides - Classroom - Teacher
Education Level: Secondary Education
Authoring Institution: N/A