题目内容
计算:19.58×66+22×91.26=
3300
3300
. 64×12.5×0.25×0.05=10
10
.分析:(1)把91.26拆成3×30.42,然后运用乘法分配律简算;
(2)把64看作2×4×8,运用乘法交换律与结合律简算.
(2)把64看作2×4×8,运用乘法交换律与结合律简算.
解答:解:(1)19.58×66+22×91.26,
=19.58×66+22×(3×30.42),
=19.58×66+66×30.42,
=66×(19.58+30.42),
=66×50,
=3300;
(2)64×12.5×0.25×0.05,
=2×4×8×12.5×0.25×0.05,
=(8×12.5)×(0.25×4)×(0.05×2),
=100×1×0.1,
=10.
=19.58×66+22×(3×30.42),
=19.58×66+66×30.42,
=66×(19.58+30.42),
=66×50,
=3300;
(2)64×12.5×0.25×0.05,
=2×4×8×12.5×0.25×0.05,
=(8×12.5)×(0.25×4)×(0.05×2),
=100×1×0.1,
=10.
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.
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