题目内容
| 下面各题,能用简便方法计算的用简便方法计算: 2.5×12.5×32 | 6.4÷2.5÷0.4 | 5.4×0.36+0.64×5.4 |
| 9÷0.75+9÷0.25 | 17.2-0.71-0.29 | 8.6+1.4÷2.5. |
(1)2.5×12.5×32
=(2.5×4)×(12.5×8),
=10×100,
=1000;
(2)6.4÷2.5÷0.4
=6.4÷(2.5×0.4),
=6.4÷1,
=6.4;
(3)5.4×0.36+0.64×5.4
=5.4×(0.36+0.64),
=5.4×1,
=5.4;
(4)9÷0.75+9÷0.25
=12+36,
=48;
(5)17.2-0.71-0.29
=17.2-(0.71+0.29),
=17.2-1,
=16.2;
(6)8.6+1.4÷2.5
=8.6+0.56,
=9.16.
=(2.5×4)×(12.5×8),
=10×100,
=1000;
(2)6.4÷2.5÷0.4
=6.4÷(2.5×0.4),
=6.4÷1,
=6.4;
(3)5.4×0.36+0.64×5.4
=5.4×(0.36+0.64),
=5.4×1,
=5.4;
(4)9÷0.75+9÷0.25
=12+36,
=48;
(5)17.2-0.71-0.29
=17.2-(0.71+0.29),
=17.2-1,
=16.2;
(6)8.6+1.4÷2.5
=8.6+0.56,
=9.16.
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