题目内容
【题目】你能想出简便方法来计算下面各题吗?(12’)
25×5+74×5+5 6.74+12.62+24.38+3.26
87-2.123-0.877 30.65-(7.65+5.4)
【答案】500 47 84 17.6
【解析】
试题分析:
25×5+74×5+5 6.74+12.62+24.38+3.26
=(25+74+1)×5 =(6.74+3.26)+(12.62+24.38)
=100×5 =10+37
=500 =47
87-2.123-0.877 30.65-(7.65+5.4)
=87-(2.123+0.877) =30.65-7.65-5.4
=87-3 =23-5.4
=84 =17.6
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