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还原问题是指题目给出的是一个数经过某些变化后的结果,要计算原来的数是多少的问题。解答这一类问题时,要根据题意,从所给的结果出发,抓住逆运算关系,由后向前一步步逆推(倒推法、还原法),做相反的运算,逐步靠拢已知条件,直到问题得到解决。在解答还原问题时,如果列综合算式,要注意括号的正确使用。
Restore the problem is given the title is a number after some changes in the results, to calculate the original number is how much the problem. When answering this kind of question, we should proceed from the result given and grasp the relation of the inverse operation from the given result, and reverse the backward one step (backward method and reduction method) to do the opposite operation and gradually close Know the conditions until the problem is solved. When answering the restore problem, pay attention to the correct use of the brackets if the column is syntactic.