| 计算下面各题. 41×101 | 4.5-2.8-0.7 | 375+450÷18×25 |
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=41×(100+1),
=4100+41,
=4141;
(2)4.5-2.8-0.7,
=4.5-(2.8+0.7),
=4.5-3.5,
=1;
(3)375+450÷18×25,
=375+25×25,
=375+625,
=1000;
(4)12÷
÷0.6,=12×0.8÷0.6,
=9.6÷0.6,
=16;
(5)[
-(
-
)]×6,=[
-
]×6,=
×6,=
;(6)12×(
+
-
),=12×
+12×
-12×
,=3+2-4,
=1.
分析:(1)把101看做100+1,运用乘法分配律简算;
(2)运用减法的性质简算;
(3)先算除法和乘法,再算加法;
(4)运用乘法分配律简算;
(5)先算小括号内的,再算中括号内的,最后算括号外的.
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.


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