PRESERVICE ELEMENTARY TEACHERS' MODELING STRATEGIES WHEN SOLVING NON-STANDARD ADDITION AND SUBTRACTION APPLICATION PROBLEMS INVOLVING ORDINAL NUMBERS

José N. Contreras

The University of Southern Mississippi

Jose.Contreras@usm.edu

The purpose of this study is to examine the modeling strategies that preservice elementary teachers use when solving non-standard subtraction and addition application problems that involve ordinal numbers. In such problems, addition or subtraction of the two given numbers produces either 1 more or 1 less than the correct solution. Thirty-four preservice elementary teachers completed a paper-and-pencil questionaire that contained 9 experimental items and 6 buffer items. Four of the nine experimental items can be solved by straightforward addition or subtraction of the two given numbers. The experimental items of the questionaire were adapted from Verschaffel, De Corte, and Vierstraete's (1999) study. Students performed poorly on the five non-standard experimental items. Out of the 170 answers, 142 (83.5%) were incorrect. The number of correct responses varied from 1 (In November 1994, the twenty-fifth annual school party took place. In what year was the school party held for the first time?) to 17 (There was a summer market in our city every summer up through 1990. Since then the summer market was canceled 7 consecutive times. In what year did the summer market restart?) The main factor accounting for the incorrect solutions was students' tendency to subtract or add the two given numbers without realizing the inappropriateness of these actions. In another paper (Contreras, 2000), I continue to examine prospective elementary teachers' difficulties with modeling non-standard arithmetic word problems.

References

Contreras, J. (2000). Preservice elementary teachers' difficulties when solving non-standard addition and subtraction application problems involving ordinal numbers. In Fernandez et. al. (2000), ), Proceedings of of the Twenty-Second Annual Meeting of the North American Chapter of the Psychology of Mathematics Education. Tucson, AZ. Columbus, Ohio: ERIC.

Verschaffel, L., & De Corte, E. (1997). Teaching realistic mathematical modeling in the elementary school: A teaching experiment with fifth graders. Journal for Research in Mathematics Education, 28(5), 577-601.