一、说教材吨的认识这部分内容是在学生认识了重量单位“克”和“千克”的基础上进行教学的。对于“吨”这个重量单位 ,学生在日常生活中很少接触 ,所以教材通过装货物的卡车、火车皮这样一组图画 ,让学生初步感知这些物品都很重 ,不能用以前学过的重量单位来表示 ,自然地引出 First, the teaching material tons of understanding This part is based on the students know the weight unit “grams” and “kg” on the basis of teaching. For the “ton” of the unit of weight, students rarely touch in daily life, so the textbooks through the loading of the truck, train hide such a set of drawings, so that students initially perceived these items are heavy, can not be used before the weight Units to express naturally lead