This article describes the use of a case report, Multiplication as original sin (Corwin, R. B. (1989). Multiplication as original sin. Journal of Mathematical Behavior, 8, 223–225), as an assignment in a mathematics course for preservice elementary teachers. In this case study, Corwin described her experience as a 6th grader when she revealed an invented algorithm. Preservice teachers were asked to write reflections and describe why Corwin’s invented algorithm worked. The research purpose was: to learn about the preservice teachers’ understanding of Corwin’s invented multiplication algorithm (its validity); and, to identify thoughtprovoking issues raised by the preservice teachers. Rather than using mathematical properties to describe the validity of Corwin’s invented algorithm, a majority of them relied on procedural and memorized explanations. About 31% of the preservice teachers demonstrated some degree of conceptual understanding of mathematical properties. Preservice teachers also made personal connections to the case report, described Corwin using superlative adjectives, and were critical of her teacher.

Recent Posts
@rmosvold on twitter
 How nice! Actually, I thought it might be you when I heard your name, Raymond (@MathEdnet)! We should talk tomorrow :) 2 months ago
 Enjoyed rehearsing rehearsals at #Novemberkonferansen with @ekazemi today! Choral counting has a lot to it! 5 months ago
 J. Skott: «Generic example of generic proofs is Gauss: 1+2+3...+100=?» #Novemberkonferansen #playonwords 5 months ago
 Next up at #Novemberkonferansen is Jeppe Skott, who talks about Goldilocks, mathematical reasoning and proof. Nice combination :) 5 months ago
 Listening to a very nice lecture on the importance of maths by Chris Budd ( people.bath.ac.uk/mascjb/) at #Novemberkonferansen 5 months ago
Archives
Meta