在教学负数时,许多学生总是把-a当成负数,这是为什么呢?本文从数学学习和心理特征的角度阐述其中的原因,并提出一些建议,希望对负数的教与学有一定的帮助.一、对字母表示数的本质认识不够清晰小学阶段从一年级至六年级,学生所学的、所接触的数通通是非负数(正数和0),天天学习的是 In teaching negative numbers, many students always take -a as a negative number. Why is this? This article explains the reasons from the perspective of mathematics learning and psychological characteristics, and puts forward some suggestions. It is hoped that it will help negative numbers to teach and learn. 1. The nature of the alphanumeric number is not clear enough. In elementary school, from the first grade to the sixth grade, the number of students’ knowledge of and contact with is non-negative (positive number and 0). Everyday learning is