解题思路:(1)运用乘法交换律简算;
(2)运用乘法分配律简算;
(3)逆用乘法分配律简算.
(1)0.125×4.78×80
=0.125×80×4.78
=10×4.78
=47.8;
(2)(0.4+40)×2.5
=0.4×2.5+40×2.5
=1+100
=101;
(3)6.9×87+6.9×14-6.9
=6.9×(87+14-1)
=6.9×100
=690.
点评:
本题考点: 运算定律与简便运算.
考点点评: 完成本题要注意分析式中数据,运用合适的简便方法计算.
解题思路:(1)运用乘法交换律简算;
(2)运用乘法分配律简算;
(3)逆用乘法分配律简算.
(1)0.125×4.78×80
=0.125×80×4.78
=10×4.78
=47.8;
(2)(0.4+40)×2.5
=0.4×2.5+40×2.5
=1+100
=101;
(3)6.9×87+6.9×14-6.9
=6.9×(87+14-1)
=6.9×100
=690.
点评:
本题考点: 运算定律与简便运算.
考点点评: 完成本题要注意分析式中数据,运用合适的简便方法计算.