速算法,是利用某些数的特征,根据四则运算的定律、性质,以及和,差、积、商的变化规律进行计算的。其思维的途径是:尽可能将数凑(或变)整;或将多位数的计算,转化为一位数的计算,从而达到计算简便迅速的目的。进行速算时,可用口算,也可用笔算,或者口算、笔算结合进行,但口算是主要的.培养学生灵活选用恰当的速算方法进行计算,可以帮助学生进一步明确数的概念,加深理解 Speed ​​algorithm, is the use of certain characteristics of the number, according to the four laws of the operation, nature, and the sum of difference, product, and business rules for the calculation. The way of thinking is: count as much as possible (or change) as much as possible; or convert multi-digit calculation into single-digit calculation, so as to achieve the goal of simple and quick calculation. When calculating the speed, you can use the port count, the pen can also be used, or the word count, pen calculation combined, but the mouth is the main .Facilities to develop students with the appropriate speed calculation method can help students to further clarify the concept of several to deepen understanding