“估算”就是借助估计来进行的有关运算,有的习题是通过估计来简化运算过程的,有的习题是通过估计创造条件进一步运算的.估算也是一种能力,它要求学生对物理量大小有较强的感知认识,能找到题目中最恰当的估计对象.有的同学对这类习题把握不准,常认为条件 “Estimation” is related calculations performed by means of estimation. Some exercises are to simplify the calculation process through estimation, and some problems are further calculated by estimating the conditions for creation. Estimation is also an ability that requires students to have physical quantities. Have a strong sense of perception, can find the most appropriate object of estimation in the title. Some students are not sure about this type of exercise, often consider the conditions