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用简便方法计算下面各题1.Ol×6.3 2.18×3.12+6.88×2.18 4.4×250.25×39+0.25 0.8×5.67×12.5 4.4×3.8+6.6×3.8-3.88.6×102

编辑:chaxungu时间:2026-04-27 11:16:09分类:小学数学题库

用简便方法计算下面各题
1.Ol×6.3 
2.18×3.12+6.88×2.18 
4.4×250.25×39+0.25 
0.8×5.67×12.5 4.4×3.8+6.6×3.8-3.8
8.6×102 (0.2+4)×25 
12.5×32×0.25.
解:(1)1.Ol×6.3
=(1+0.01)×6.3,
=1×6.3+0.01×6.3,
=6.3+0.063,
=6.363;

(2)2.18×3.12+6.88×2.18
=(3.12+6.88)×2.18,
=10×2.18,
=21.8;

(3)4.4×25
=(4+0.4)×25,
=4×25+0.4×25,
=100+10,
=110;

(4)0.25×39+0.25
=(39+1)×0.25,
=40×0.25,
=10;

(5)0.8×5.67×12.5
=0.8×12.5×5.67,
=10×5.67,
=56.7;

(6)4.4×3.8+6.6×3.8-3.8
=(4.4+6.6-1)×3.8,
=10×3.8,
=38;

(7)8.6×102
=8.6×(100+2),
=8.6×100+8.6×2,
=860+17.2,
=877.2;

(8)(0.2+4)×25
=0.2×25+4×25,
=5+100,
=105;

(9)12.5×32×0.25
=(12.5×8)×(4×0.25),
=100×1,
=100.
分析:(1)可将1.01拆分为1+0.01后根据乘法分配律计算;
(2)(4)(6)(8)可根据乘法分配律计算;
(3)将1.4拆分为4+0.4后根据乘法分配律计算;
(5)可根据乘法交换律计算;
(7)可将102拆分为100+2后根据乘法分配律计算;
(9)可根据将32拆分为8×4后根据乘法结合律计算.
点评:完成本题要细心分析题目中数据的特点及内在联系,然后运用合适的方法计算.