递等式计算,能简便的就简便计算.
(1)9.2×1.5÷3
(2)19.03-5.53-0.37
(3)86÷(8.6×25)
(4)6.3×101-6.3
(5)1.8÷3.6×(0.9+1.2)
(6)12÷0.125
(7)18.21+25.93+1.79
(8)59.6×18+59.6×81+59.6
(9)33.02-(148.4-90.85)÷2.5
(10)[33.3-(17.4+3.1)]×6.05.
解:
(1)9.2×1.5÷3,
=13.8÷3,
=4.6;
(2)19.03-5.53-0.37,
=19.03-(5.53+0.37),
=19.03-5.9,
=13.13;
(3)86÷(8.6×25),
=86÷8.6÷25,
=10÷25,
=0.4;
(4)6.3×101-6.3,
=6.3×(100-1),
=6.3×100,
=630;
(5)1.8÷3.6×(0.9+1.2),
=1.8÷3.6×2.1,
=0.5×2.1,
=1.05;
(6)12÷0.125,
=12÷0.125÷8×8,
=12÷(0.125×8)×8,
=12÷1×8,
=12×8,
=96;
(7)18.21+25.93+1.79,
=(18.21+1.79)+25.93,
=20+25.93,
=45.93;
(8)59.6×18+59.6×81+59.6,
=59.6×(18+81+1),
=59.6×100,
=5960;
(9)33.02-(148.4-90.85)÷2.5,
=33.02-57.55÷2.5,
=33.02-23.02,
=10;
(10)[33.3-(17.4+3.1)]×6.05,
=[33.3-20.5]×6.05,
=12.8×6.05,
=77.44.
分析:(1)先算乘法,再算除法;
(2)根据加法的性质进行简算;
(3)根据除法的性质进行简算;
(4)根据乘法分配律进行简算;
(5)先算加法,再算除法,最后算乘法;
(6)原式先除以8,再乘8,然后再根据除法的性质进行简算;
(7)根据加法交换律和结合律进行简算;
(8)根据乘法分配律进行简算;
(9)先算小括号里面的减法,再算除法,最后算括号外面的减法;
(10)先算加法,再算减法,最后算乘法.
点评:考查了运算定律与简便运算,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律简便计算.