能簡算的要簡算.
125.7×18.5-25.7×18.5
58.8÷(0.6×0.7)÷0.02
27÷0.25
0.357÷(0.75×0.4)
10.1×87
0.45×78.2+20.8×0.45+0.45.
解:①125.7×18.5-25.7×18.5,
=(125.7-25.7)×18.5,
=100×18.5,
=1850;
②58.8÷(0.6×0.7)÷0.02,
=58.8÷0.42÷0.02,
=140÷0.02
=7000;
③27÷0.25,
=(27×4)÷(0.25×4),
=108÷1,
=108;
④0.357÷(0.75×0.4),
=0.357÷0.3,
=1.19;
⑤10.1×87,
=(10+0.1)×87,
=10×87+0.1×87,
=870+8.7,
=878.7;
⑥0.45×78.2+20.8×0.45+0.45,
=(78.2+20.8+1)×0.45,
=100×0.45,
=45.
分析:①運用乘法分配律,進行簡算;
②根據小數四則混合運算的運算順序進行解答;
③先根據商不變性質,被除數和除數同時乘4,然后求出商;
④先算小括號里面的,再算除法;
⑤把10.1分成10+0.1,然后運用乘法分配律進行計算即可;
⑥運用乘法分配律,進行簡算即可.
點評:完成本題要注意分析式中數據,運用合適的簡便方法計算.