用简便方法计算
(1)0.25×32×0.5
(2)×17-12×
(3)18×(+-+)
(4)(50×49×48)÷(25×24)
网友回答
解:
(1)0.25×32×0.5,
=0.25×(4×8)×0.5,
=(0.25×4)×(8×0.5),
=1×4,
=4;
(2)×17-12×,
=×(17-12),
=×5,
=3;
(3)18×(+-+),
=18×+18×-18×+18×,
=9+12-8+15,
=21-8+15,
=13+15,
=28;
(4)(50×49×48)÷(25×24),
=(50×49×2×24)÷(25×4×6),
=(50×2×24×49)÷(25×4×6),
=(100×24×49)÷(100×6),
=2400×49÷600,
=2400÷600×49,
=4×49,
=196.
解析分析:(1)32=4×8,根据乘法交换律和结合律进行简算;
(2)根据乘法分配律进行简算;
(3)根据乘法分配律进行简算;
(4)48=2×24,24=4×6,再根据乘法交换律和结合律进行简算.
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.