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教材分析小数乘以小数是在学生已经掌握了小数乘以整数、整数乘以小数的计算方法基础上进行教学的。因此,这节课的教学重点是小数乘法法则的理解和积里小数点位置的确定。对于小数乘法中,先把两个因数转化为整数求得的积,要再缩小原来两个因数共扩大的倍数,才能求得原式的积,学生理解有困难,是学习的难点,由于“两个因数分别扩大a倍、b倍,积就要扩大a×b倍”这一积的变化规律教材里未出现过,为了突破这一难点,可以让学生先根据13×21=273,很快说出下面各题的积:130×2100,1300×210,1300×2100,
Text Analysis Fractional decimals are taught on the basis that students have mastered decimal numbers multiplied by integers, and integers multiplied by decimals. Therefore, the teaching of this lesson focuses on the understanding of the principle of fractional multiplication and the determination of the position of the decimal point in the product. For the fractional multiplication, the first two factors into integer product, to reduce the original multiples of the two factors in total expansion in order to obtain the original product, students have difficulty understanding, is the difficulty of learning, because “ The two factors were expanded a times, b times, the product will be expanded a × b times ”The law of change in the textbook has not appeared, in order to break through this difficulty, students can first according to 13 × 21 = 273, very Express the product of the following questions: 130 × 2100, 1300 × 210, 1300 × 2100,