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前不久,一位老师执教乘法运算定律中的“交换律、结合律”,引发了我的一点思考。1.过程描述在利用乘法交换律和结合律简便计算的一次练习中,老师出示习题,并问哪些算式可以简算。学生一一做了回答。其中125×9一题,老师为了让学生明白运用乘法交换律、结合律不能使计算简便,故
Not long ago, a teacher coached the principle of multiplicative law “exchange law, combined with the law,” triggered me a little thought. 1. Process Description In an exercise that is easily calculated using the law of multiplication and the law of conjugation, the teacher presents the exercises and asks what formulas can be calculated in simple terms. The students responded one by one. One 125 × 9 a question, the teacher in order to allow students to understand the use of multiplication law of exchange, the law can not make the calculation simple, so