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笔者今年执教五年级数学。在教学体积,这一类型的题时引起了我的思考。在北师大版第十册数学第49页中有这样一道题:“牙膏盒长15厘米,宽和高都是3厘米。现有一纸箱,内侧的尺寸是长60厘米,宽和高都是30厘米,这个纸箱中最多能放多少盒牙膏?”(课本中有图形)学生在学习了长方体的体积计算后对于这样的题他们很自然就会想到:先算一个牙膏盒的体积,再算纸箱的体积,然后用纸箱的体积÷牙膏盒的体积。对于这道题学生这样做当然是毋庸置疑的。教参中是这样说的:可以引导学生先研究解决问题的思路,必要时,教师可以借助一些直观物体
The author taught fifth grade math this year. In the teaching volume, this type of question aroused my thinking. There is such a question in the sixth division of the National Taiwan Normal University mathematics page 49: “Toothpaste box length 15 cm, width and height are 3 cm. There is a cardboard box, the inside size is 60 cm long, wide and high Is 30 cm, how many cartons of toothpaste can be placed in this box? ”(There is a picture in the textbook) After the student learns the volume of the cuboid, it is natural for them to think of this: First calculate the volume of a toothpaste box, Then calculate the volume of the carton, and then use the volume of the carton ÷ volume of the toothpaste box. Of course, students do not doubt this. Teaching reference is to say: can guide students to study the problem-solving ideas, if necessary, teachers can resort to some intuitive objects