论文部分内容阅读
在日常生活、学习和工作中,人们往往自觉或不自觉地运用“估算”,如星期天去银川买东西花了八十多元钱、听讲座的教师约有100多人、今年小麦亩产量平均400多公斤等。曾有专家做过统计,一个人在一天的活动中,对和、差、积、商估计的次数大大超过精确计算次数。 估算的内容在小学数学教材中虽然没有单独安排章节,但在各册教材的练习中却出现了很多。从第三册(五年制)就开始出现了量一量你的一手拃(zhǎ)、一庹(tuǒ,即两臂平伸后两手间的距离)、一步长多少厘米;在横线上填上适当的单位名称:蜡笔长6_,大头针长24_,楼房高15_等。九年制义务教育小学数学教材中增加了简易估算的教学内容,以便让学生掌握一些估算的方法,在估算的过程中培养他们的分析能力和实际应用能力。一般来说,精确计算是仔细的、微观的,而估算则是粗略的、宏观的。估算有利于培养学生的想象能力与概括能力。因此,教学中教师要重视估算。
In daily life, study and work, people often consciously or unconsciously use the “estimate”, such as going to Yinchuan Sunday to spend more than 80 yuan to attend the lecture about about 100 teachers, this year's average yield of wheat per mu More than 400 kilograms. Some experts have done statistics, a person's activities in the day, the sum, difference, product, the number of estimates greatly exceeded the exact number of calculations. Although there are no separate chapters in the elementary mathematics textbooks, there are many estimates in the textbook exercises. From the third book (five years) began to appear on the amount of your hand, a 庹 (tu arms, that is, arms stretched between the distance between the two hands), how many centimeters a step; on the horizontal line Fill in the appropriate unit name: crayon length 6_, pin length 24_, building high 15_ and so on. Nine-year compulsory primary school mathematics textbooks to increase the simple estimation of teaching content, in order to allow students to master some estimation methods in the estimation process to develop their analytical skills and practical ability. In general, precise calculations are careful and microscopic, while estimates are rough and macroscopic. Estimation is conducive to the cultivation of students' imagination ability and generalization ability. Therefore, teaching teachers should pay attention to the estimation.