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(一)教学目标 1.记忆:①记住小数乘法的意义和计算法则;②记住用“四舍五入”法取积的近似值,保留整数或几位小数所表示的精确度;③记住小数乘法的珠算法则;④记住除数是整数及除数是小数的小数除法法则;⑤记住循环小数、循环节、纯循环小数、混循环小数的定义及比较循环小数大小的方法。 2.理解:①理解一个因数或两个因数都扩大(缩小)10倍、100倍、……所引起的积的变化规律;②懂得在近似值里小数末尾的零不能随意去掉的理由;③理解“当被乘数大于0时,乘数比1小,乘得的积就比
(A) teaching objectives 1 memory: ① remember the meaning of decimal multiplication and the rule of calculation; ② remember to use the “rounding” method to take the approximate value of the product, keep the integer or decimal precision represented; ③ remember that fractional multiplication The bead algorithm; ④ remember that the divisor is an integer and the divisor is a fractional decimal division rule; ⑤ remember the cycle of decimals, loop, pure cycle decimal, mixed cycle decimal definition and comparison of cyclic decimal size. 2. Understand: ① understand a factor or both factors are expanded (narrowed) 10 times, 100 times, ... ... caused by the law of changes in the product; ② know in the approximation decimal zero can not be removed reason; ③ understanding "When the multiplicand is greater than 0, the multiplier is smaller than 1 and the multiplied product is more than that