设计意图:本课是北师大版小学数学二年级下册第二单元混合运算的教学内容。主要是引导学生体会四则运算的意义,经历与他人交流算法的过程,能灵活运用不同的方法解决问题,并能对结果进行合理的判断。另外,要让学生体会到数学的价值,感觉到数学充满趣味,而且与生活密切联系。在本 Design intent: This course is a teaching content of the second unit hybrid computing of the second grade of the second grade undergraduates of Beijing Normal University Edition. Mainly to guide students to understand the significance of the four operations, experiential exchange process with others, can use different methods to solve problems, and can reasonably judge the results. In addition, to make students appreciate the value of mathematics, feel mathematics is full of fun, but also closely linked with life. In this