【题目】小明把7.25-(m+2.25)算成了7.25-m+2.25。他这样计算得到的结果,比正确的结果大还是小?大或小多少?【预设】这是我在教学苏教版教材五年级上册小数四则混合运算之后要求学生自主解答的一道思考题。主要的目的,一是为了考查学生对小数四则混合运算的顺序以及相关运算律和运算性质的理解情况,二是为学生锻炼推理能力、进一步发展数 [Topic] Xiao Ming calculated 7.25- (m + 2.25) as 7.25-m + 2.25. What is the result of his calculation, bigger or smaller than the correct result? Big or Small? [Default] This is a question that I asked the students to answer independently after I mixed up four decimal places in the fifth grade of the teaching materials of the Sujiao Textbook. The main purpose is to examine students’ understanding of the order of the four mixed arithmetic operations and their relative understanding of the law and nature of operations and the second is to provide students with reasoning abilities and further development