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用简便方法计算下面各题.①68+247+132②264+99③400-136④243-98.

题目详情
用简便方法计算下面各题.
①68+247+132
②264+99
③400-136
④243-98.
▼优质解答
答案和解析
①68+247+132
=(68+132)+247
=200+247
=447

②264+99
=264+100-1
=364-1
=363

③400-136
=400-100-36
=300-36
=264

④243-98
=243-(100-2)
=243-100+2
=143+2
=145