教材习题都是经过专家反复研讨、推敲后确定的,每道题的设置都有一定的合理性。教材习题的加工使用不能盲目、随意,应该理解教材意图,遵循以学生发展为本的理念。本期“问题研讨”栏目中《认识整亿数》的课后习题,其设计意图是让学生进行两次推算,即1000万枚是60吨,1亿枚是600吨。需要学生进行“渐进式”的连续推想。通过这样的练习,既让学生感受到“满十进一”的计数方法,同时也发 Textbook exercises are repeatedly discussed by experts, determined after scrutiny, the setting of each question has a certain rationality. The processing of textbook exercises can not be blind, random, should understand the teaching materials intended to follow the concept of student development. In this issue of “Problem Discourse”, the “After-Know-Whole-Million” class exercises are designed to allow students to make two inferences: 10 million are 60 tons and 100 million are 600 tons. Need students to “progressive” continuous projection. Through such exercises, students are not only allowed to feel “over ten” count method, but also made