**ERIC Number:**EJ1082545

**Record Type:**Journal

**Publication Date:**2015-Nov

**Pages:**8

**Abstractor:**ERIC

**ISBN:**N/A

**ISSN:**ISSN-1072-0839

**EISSN:**N/A

12 Math Rules That Expire in the Middle Grades

Karp, Karen S.; Bush, Sarah B.; Dougherty, Barbara J.

Mathematics Teaching in the Middle School, v21 n4 p208-215 Nov 2015

Many rules taught in mathematics classrooms "expire" when students develop knowledge that is more sophisticated, such as using new number systems. For example, in elementary grades, students are sometimes taught that "addition makes bigger" or "subtraction makes smaller" when learning to compute with whole numbers, only to find that these rules expire when they begin computing with integers. However, middle-grades students, especially those who are struggling, often try to force-fit the rules that they remember from the elementary grades to new concepts or skills. In this article, the authors present 12 persistent rules that expire. These are "rules" that have been found prevalent for many years of working with students, from mathematics education literature, or in some cases, rules that the authors themselves have taught and later regretted. In each case, they offer mathematically correct and more helpful alternatives. The 12 rules that expire are: (1) KFC: Keep-Flip-Change; (2) Use the factor rainbow to factor; (3) The absolute value is just the number; (4) Multiplication is repeated addition; (5) PEMDAS: Please Excuse My Dear Aunt Sally; (6) A solution to an equation must be in the form x = ?; (7) The "Butterfly Method" for comparing fractions; (8) The most you can have is 100 percent of something; (9) Two negatives make a positive; (10) Use keywords to solve word problems; (11) A variable represents a specific unknown; and (12) FOIL: First, Outer, Inner, Last.

Descriptors: Mathematics Instruction, Secondary School Mathematics, Middle School Students, Standards, Mathematical Concepts, Vocabulary, Comprehension, Mathematical Logic, Multiplication, Addition, Mnemonics, Problem Solving, Equations (Mathematics), Word Problems (Mathematics), Common Core State Standards

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:**Secondary Education; Middle Schools; Junior High Schools

**Audience:**Teachers

**Language:**English

**Sponsor:**N/A

**Authoring Institution:**N/A

**Grant or Contract Numbers:**N/A