Inaccurate mental computation : identifying flawed thinking

Abstract

This paper reports on a study of five, Year 2 students’ strategy choice, flexibility and accuracy when answering 20 addition and subtraction mental computation questions. All five students were identified as being inaccurate. However, two students employed a range of calculation strategies while the other three students remained inflexible in their strategy choice, choosing low order strategies. Individual interviews were conducted to identify these aspects of calculation. Two conceptual flowcharts developed by Heirdsfield (2001b) were utilised to identify factors and relationships between factors that impact on mental computation. Use of these flowcharts provides an avenue for identification of the breakdown in the structures thereby providing an understanding of where the child is operating and how they may be moved forward.