用簡便方法計算(要求寫出簡算過程)
1.24+14.95+8.76-4.95
52.7-5.27-2.7
35×201
4500÷25÷4
125×32
654××99+346×99.
解:(1)1.24+14.95+8.76-4.95,
=(1.24+8.76)+(14.95-4.95),
=10+10,
=20;
(2)52.7-5.27-2.7,
=(52.7-2.7)-5.27,
=50-(5+0.27),
=50-5-0.27,
=45-0.27,
=44.73;
(3)35×201,
=35×(200+1),
=35×200+35,
=7000+35,
=7035;
(4)4500÷25÷4,
=4500÷(25×4),
=4500÷100,
=45;
(5)125×32,
=(125×8)×4,
=1000×4,
=4000;
(6)654×99+346×99,
=(654+346)×99,
=1000×99,
=99000.
分析:(1)(2)運用加法交換律和結合律簡算;
(3)把201看作200+1,運用乘法分配律簡算;
(4)運用除法的性質簡算;
(5)把32看作8×4,運用乘法結合律簡算;
(6)運用乘法分配律簡算.
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.