题目内容
脱式计算(能简算的要简算) 1.18×2.58+0.5+1.42×1.18 |
(21.85-17.5)×(0.45÷0.9) |
1.75×(0.1÷0.2)-0.18÷0.9 | 93.6÷[(54.8+45.2)×(6-5.46)]. |
分析:(1)运用乘法分配律简算;
(2)两个括号同时计算,最后算乘法;
(3)先算括号内的,再算乘法和除法,最后算减法;
(4)先算小括号内的,再算中括号内的,最后算括号外的.
(2)两个括号同时计算,最后算乘法;
(3)先算括号内的,再算乘法和除法,最后算减法;
(4)先算小括号内的,再算中括号内的,最后算括号外的.
解答:解:(1)1.18×2.58+0.5+1.42×1.18
=1.18×(2.58+1.42)+0.5
=1.18×4+0.5
=4.72+0.5
=5.22;
(2)(21.85-17.5)×(0.45÷0.9)
=4.35×0.5
=2.175;
(3)1.75×(0.1÷0.2)-0.18÷0.9
=1.75×0.5-0.2
=0.875-0.2
=0.675;
(4)93.6÷[(54.8+45.2)×(6-5.46)]
=93.6÷[100×0.54]
=93.6÷54
=
.
=1.18×(2.58+1.42)+0.5
=1.18×4+0.5
=4.72+0.5
=5.22;
(2)(21.85-17.5)×(0.45÷0.9)
=4.35×0.5
=2.175;
(3)1.75×(0.1÷0.2)-0.18÷0.9
=1.75×0.5-0.2
=0.875-0.2
=0.675;
(4)93.6÷[(54.8+45.2)×(6-5.46)]
=93.6÷[100×0.54]
=93.6÷54
=
234 |
135 |
点评:考查了小数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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