小数乘法法则在教材上,是分三段安排的.即先教小数乘以整数,再教整数乘以小数,最后教小数乘以小数.这样由特殊到一般,虽可分散难点,但很客易遇到麻烦:教前面两个内容时,由于积的小数位数恰与因数的小数位数一样,列成竖式,客易给学生造成直观上的错觉——积的小数点要与因数的小数点对齐,这恰好与前面学的小数加减法中结果的小数点 Fractional law of multiplication in the textbook, is divided into three sections, that is, pre-school multiplied by an integer, and then teach the whole number multiplied by a decimal, finally taught decimals multiplied by a decimal. This from special to general, although scattered difficult, but very off Easy to encounter trouble: to teach the first two contents, as the product of the decimal places exactly the same as the number of decimal places, into a vertical, easy to give students a visual illusion - the product of the decimal point and the factor Of the decimal point alignment, which coincides with the previous decimal addition and subtraction of the results of the decimal point