用简便方法计算下面各题.
(1)384-198??????????????????(2)208+699(3)125×32????????????????????(4)630÷35÷2.
网友回答
解:(1)384-198,
=384-(200-2),
=384-200+2,
=186;
(2)208+699,
=208+(700-1),
=208+700-1,
=907;
(3)125×32,
=125×8×4,
=1000×4,
=4000;
(4)630÷35÷2,
=630÷(35×2),
=630÷70,
=9.
解析分析:(1)把198看作200-1,运用加法的性质简算;
(2)把699看作700-1,然后再计算;
(3)把32看作8×4,运用乘法结合律简算;
(4)运用除法的性质简算.
点评:完成本题,要注意分析式中数据,运用合适的简便方法计算.