**ERIC Number:**EJ916993

**Record Type:**Journal

**Publication Date:**2011-Mar

**Pages:**8

**Abstractor:**ERIC

**Reference Count:**7

**ISBN:**N/A

**ISSN:**ISSN-1072-0839

Making Sense of Decimal Multiplication

Rathouz, Margaret M.

Mathematics Teaching in the Middle School, v16 n7 p430-437 Mar 2011

In the elementary grades, students learn procedures to compute the four arithmetic operations on multidigit whole numbers, often by being shown a series of steps and rules. In the middle grades, students are then expected to perform these same procedures, with further twists. The Reasoning and Proof Process Standard suggests that students need to reason about the math that they are learning to make sense of the content. The Representation Process Standard explores the importance of creating and using representations to communicate mathematical ideas and interpret physical and mathematical phenomena. What reasoning and which representations might middle-grades students use to make sense of the procedures for multiplying decimals? Students face several challenges as they transition from whole-number multiplication to decimal fraction multiplication. Teachers should have a deep understanding of the mathematics so that they can better support middle school students' sense making. To build student confidence, the author suggests to relate decimals to whole-number operations, geometry, and measurement. (Contains 7 figures.)

Descriptors: Arithmetic, Mathematics Instruction, Multiplication, Mathematical Logic, Mathematics Skills, Validity, Mathematical Concepts, Middle School Students, Secondary School Mathematics, Geometry

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:**Middle Schools

**Audience:**Teachers

**Language:**English

**Sponsor:**N/A

**Authoring Institution:**N/A