题目内容
计算下面各题,能简算的要用简便方法算.
201-5406÷51 | 1.8×(21÷1.4) | 3-4×2.33×0.25 |
(-)×(+) | ÷[-(0.15+)]. |
解:(1)201-5406÷51,
=201-106,
=95;
(2)1.8×(21÷1.4),
=1.8×15,
=27;
(3)3-4×2.33×0.25,
=3-(4×0.25)×2.33,
=3-1×2.33,
=3-2.33,
=0.67;
(4)(-)×(+),
=×,
=;
(5)÷[-(0.15+)],
=÷[-0.6],
=÷,
=7.5.
分析:(1)先算除法,再算减法,
(2)先算小括号里的除法,再算括号外的乘法,
(3)运用乘法的交换律、结合律进行简算,
(4)先算小括号里的运算,再算乘法,
(5)先算小括号里的加法,再算中括号里的减法,最后算除法.
点评:考查了四则混合运算的运算顺序,注意有括号的运算.
=201-106,
=95;
(2)1.8×(21÷1.4),
=1.8×15,
=27;
(3)3-4×2.33×0.25,
=3-(4×0.25)×2.33,
=3-1×2.33,
=3-2.33,
=0.67;
(4)(-)×(+),
=×,
=;
(5)÷[-(0.15+)],
=÷[-0.6],
=÷,
=7.5.
分析:(1)先算除法,再算减法,
(2)先算小括号里的除法,再算括号外的乘法,
(3)运用乘法的交换律、结合律进行简算,
(4)先算小括号里的运算,再算乘法,
(5)先算小括号里的加法,再算中括号里的减法,最后算除法.
点评:考查了四则混合运算的运算顺序,注意有括号的运算.
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