论文部分内容阅读
在小学数学教学中,关于估算教学常常听到这样的声音:“如何选择适合情境的估算方法?”“四舍五入法是解决估算问题的最好方法吗?”等等。下面带着这些问题结合两个案例谈谈估算教学。一、发现问题案例1:一位教师执教北师大版三年级上册“捐书活动”(三位数的连加运算)这节课。情境如下图:在解决“哪个年级捐的书多”这个问题时,教师引导学生先思考,并要求学生说一说你是怎么想的。(目的是用估算的方法思考哪个年级捐的书多)
In elementary mathematics teaching, we often hear the following about the teaching of estimation: “How to choose a suitable method for estimating the situation? ” “Is the best way to solve the estimation problem?” Below with these two problems to talk about the estimation of teaching. First, the discovery of the problem Case 1: A teacher coached the third edition of the Beijing Normal University on the book “donation activities ” (three-digit even with the operation) of this lesson. The situation is as follows: When solving the problem of “Which grade donates more books?”, The teacher guides the students to think first and asks the students to talk about what you think. (The purpose is to use an estimation method to think which grade donated more books)