小学数学第四册第一单元中“被乘数的中间、末尾有0的乘法”,是本单元的教学难点。为了突破这一难点,教材在编排上注意了如下几点:第一,按照由易到难的顺序,先安排被乘数中间有0的乘法,后安排被乘数末尾有0的乘法;第二,先借助空盘图进行演示,再利用乘法交换律进行推导, The fourth unit of elementary mathematics, the first unit in the “multiplicand in the middle, there is a 0 at the end of the multiplication,” is the unit of teaching difficult. In order to break through this difficulty, the textbook pays attention to the following points in the orchestration: First, according to the order from easy to difficult, first arrange the multiplicand to have 0's multiplication in the middle, and arrange the multiplication to have 0 at the end of the multiplier; Second, the first demonstration with empty disk charts, and then use the law of multiplication exchange derivation,