57+28=85【教学实况】这是学习“两位数加两位数”口算的教学片段。教师出示例题:57+28师:这道题,用口算的方法怎样算?你有什么好方法?和同桌的同学说说。教室里立刻响起了激烈的讨论声。不一会,许多同学纷纷举起了手。生1:我是先算57+20=77,再算77+8=85。教师在黑板上板书生1? 57 +28 = 85 [Teaching Live] This is learning the “two-digit plus two-digit” count of mouth video section. Teachers to produce examples: 57 +28 division: This question, how to calculate the method of calculating? What are your good ways? And classmates at the same table to talk about. There was an intense discussion immediately in the classroom. A short while, many students have raised their hands. Health 1: I first count 57 +20 = 77, and then count 77 +8 = 85. Teacher on the blackboard board scholar 1?