“负数”将小学阶段的数系从非负有理数扩张为有理数域。“负数”教学应关注概念的本质,负数不仅仅是表示相反意义的量,同样的事物由于基准的不同,相反意义的量表达也不一样。同时,利用形象直观的特性要让“负数”教学成为“数轴”的生长点,利用实物模型培养孩子的数感。教学过程中要力求追溯数学概念本质,这才是提升数学有效教学的基石。 “Negative ” expands the number of elementary school stages from non-negative to rational. “Negative ” teaching should pay attention to the essence of the concept. Negative numbers not only represent the amount of the opposite meaning, but also because of the difference of the same thing. At the same time, the use of visual characteristics of the image to make “negative ” teaching become “number of axes ” growing point, the use of physical model to cultivate children’s sense of number. In the process of teaching, we should try our best to trace the essence of mathematical concepts, which is the cornerstone of improving the effective teaching of mathematics.