题目内容
用自己喜欢的方法计算.
35.47+39.88-12.37 | 93.21-5.99-14.01 |
15.37+28.94+4.63+1.06 | 42.37-(12.37-9.78) |
分析:(1)运用加法交换律与结合律简算;
(2)(4)运用减法的性质简算;
(3)运用加法交换律与结合律简算.
(2)(4)运用减法的性质简算;
(3)运用加法交换律与结合律简算.
解答:解:(1)35.47+39.88-12.37,
=(35.47-12.37)+39.88,
=23.1+39.88,
=62.98;
(2)93.21-5.99-14.01,
=93.21-(5.99+14.01),
=93.21-20,
=73.21;
(3)15.37+28.94+4.63+1.06,
=(15.37+4.63)+(28.94+1.06),
=20+30,
=50;
(4)42.37-(12.37-9.78),
=42.37-12.37+9.78,
=30+9.78,
=39.78.
=(35.47-12.37)+39.88,
=23.1+39.88,
=62.98;
(2)93.21-5.99-14.01,
=93.21-(5.99+14.01),
=93.21-20,
=73.21;
(3)15.37+28.94+4.63+1.06,
=(15.37+4.63)+(28.94+1.06),
=20+30,
=50;
(4)42.37-(12.37-9.78),
=42.37-12.37+9.78,
=30+9.78,
=39.78.
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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