计算(1)27+[0.3×(8-)](2)2012÷-3×2012(3)[1.9+19%×(5.8-4)]+(53×+30.6×0.25)

发布时间:2020-08-12 09:21:23

计算
(1)27+[0.3×(8-)]
(2)2012÷-3×2012
(3)[1.9+19%×(5.8-4)]+(53×+30.6×0.25)

网友回答

解:(1)27+[0.3×(8-)],
=27+[×],
=27+,
=27;

(2)2012÷-3×2012,
=2012×-3×2012,
=2012×(-3),
=2012×2,
=4024;

(3)[1.9+19%×(5.8-4)]+(53×+30.6×0.25),
=[1.9×(5.8-4.8+1)]+(53×+30.6×),
=(1.9×2)+(53+30.6)×,
=3.8+83.6×,
=3.8+20.9,
=24.7.
解析分析:(1)先算小括号内的,再算中括号内的,最后算括号外的;
(2)把除法改为乘法,运用乘法分配律简算;
(3)把19%和4化为小数,把0.25化为分数,两个括号都可运用乘法分配律简算.

点评:考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
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