Author Pam Harris argues that teaching real math--math that is free of distortions--will reach more students more effectively and result in deeper understanding and longer retention. This book is about teaching undistorted math using the kinds of mental reasoning that mathematicians do. Memorization tricks and algorithms meant to make math…

Our work investigated how six primary school students used a non-traditional method for adding and subtracting: the ABN method, a Spanish acronym for Open (method) Based on Numbers. Commognitive theory [Sfard, A. 2008. "Thinking as Communicating: Human Development, the Growth of Discourses, and Mathematizing." New York: Cambridge…

This observational study used data from 270 second-grade students to investigate the association between students' strategy use for multidigit addition and subtraction and their mathematics achievement. Based on strategies they used during a mathematics interview, students were classified into the following strategy groups: (a) standard algorithm,…

Different methods of subtracting are described; the equal additions and the decomposition methods are discussed in detail. (DT)

Two sequences of activities were developed to provide instruction on the algorithms for addition and subtraction of two-digit numbers. In the integrated sequence (I) the mechanics of "carrying" and "borrowing" were treated as a single process "regrouping." In the sequential treatment (S) the addition algorithm was developed before the subtraction…

Two sequences of activities were developed to provide instruction on the algorithms for addition and subtraction of two-digit numbers. In the integrated sequence (I) the mechanics of "carrying" and "borrowing" were treated as a single process "regrouping." In the sequential treatment (S) the addition algorithm was developed before the subtraction…

Reviews the historical use of each of the three algorithms used for subtraction in the United States: (1) the equal additions; (2) the decomposition; and (3) the Austrian method. Discusses the modification to the decomposition algorithm and gives a brief overview of the current status of subtraction algorithms. Contains 12 references. (Author/ASK)

A modified method of regrouping the minuend for subtraction is described. This more flexible method decreases the number of steps in the subtraction process and in checking the regrouping. (SD)

Four algorithms for subtraction are described: borrow and pay back,'' equal additiions, shopkeepers' subtraction,'' and decomposition. (DT)

The author taught one group using the traditional subtraction algorithm and one using an equal additions algorithm. Students in the latter group showed greater success than the former. (SD)

A current method of teaching long division using repeated subtraction is analyzed as being an example of a sound mathematical method that falls into disrepute when it results in unnecessary, length calculations. (MP)

Reviews the historical development of subtraction algorithms used in the United States. Discusses different algorithms used and developed throughout history that had a major impact on the way subtraction is taught today. (Contains 22 references.) (ASK)

A concrete approach to subtraction problems with minuends to 19 is presented. (MP)