计算下列各题,能简算的要简算.
(1).1.5×8.4+3×+15×l0%;
(2)+;
(3);
(4);
(5)1110÷;
(6)5-.
网友回答
解:
(1)1.5×8.4+3×+15×l0%,
=1.5×8.4+1.5×0.l+3×,
=1.5×(8.4+0.1)+0.9,
=1.5×8.5+0.9,
=12.75+0.9,
=13.65;
(2)+,
=+(1-),
=+,
=;
(3),
=,
=,
=1+,
=1;
(4),
=,
=,
=,
=;
(5)1110÷,
=1110÷,
=1110÷[65-55],
=1110÷10,
=111;
(6)5-,
=5-,
=5-[3-2.5]÷0.125,
=5-0.5÷0.125,
=5-4,
=1.
解析分析:(1)根据乘法分配律进行计算;
(2)先算乘法,再算减法,最后算加法;
(3)根据乘法分配律进行计算;
(4)根据连减的性质计算括号里面的,最后算除法;
(5)根据乘法分配律进行计算;
(6)根据连减的性质计算括号里面的,再算除法,最后算减法.
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.