题目内容
用简便方法计算(要求写出简算过程)
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)运用加法交换律和结合律简算;
(3)把201看作200+1,运用乘法分配律简算;
(4)运用除法的性质简算;
(5)把32看作8×4,运用乘法结合律简算;
(6)运用乘法分配律简算.
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.
=(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)运用加法交换律和结合律简算;
(3)把201看作200+1,运用乘法分配律简算;
(4)运用除法的性质简算;
(5)把32看作8×4,运用乘法结合律简算;
(6)运用乘法分配律简算.
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.
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