论文部分内容阅读
求同存异例:学校食堂上午买来2袋面粉和5袋大米共重550千克,下午买来3袋面粉和4袋大米共重510千克。每袋面粉、每袋大米各重多少千克?本题难在上午、下午买的面粉和大米的袋数都不相同,用假设法可促使面粉袋数相同。大米袋数相异,可以从两个差(大米袋数的差和总重量的差)来寻求问题的答案。为了说明问题,列表如下:
Seeking common ground Exception: School canteens bought 2 bags of flour and 5 bags of rice weighing 550 kg in the morning. In the afternoon, they bought 3 bags of flour and 4 bags of rice weighing 510 kg in total. Each bag of flour, how many kg each bag of rice? This problem is difficult in the morning and afternoon to buy flour and rice bags are not the same, with the assumptions can promote the same number of flour bags. The number of sacks varies, and the answer to the question can be found from the two differences (the difference between the number of sacks and the total weight). To illustrate the problem, the list is as follows: