脱式计算(能简算的要简算.)
7.8+4.56+2.2????0.75×6.4-0.75×5.4?????78÷0.25÷0.4??????????9.9×57.
脱式计算(能简算的要简算.)7.8+4.56+2.2????0.75×6.4-0.75×5.4?????78÷0.25÷0.4??????????9.9×57.
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解决时间 2021-01-20 13:18
- 提问者网友:龅牙恐龙妹
- 2021-01-20 06:23
最佳答案
- 五星知识达人网友:怙棘
- 2020-10-12 18:22
解:(1)7.8+4.56+2.2,
=(7.8+2.2)+4.56,
=10+4.56,
=14.56;
(2)0.75×6.4-0.75×5.4,
=0.75×(6.4-5.4),
=0.75×1,
=0.75;
(3)78÷0.25÷0.4,
=78÷(0.25×0.4),
=78÷0.1,
=780;
(4)9.9×57,
=(10-0.1)×57,
=10×57-0.1×57,
=570-5.7,
=564.3.解析分析:(1)运用加法交换律简算;
(2)运用乘法分配律简算;
(3)运用除法的性质简算;
(4)把9.9看作10-0.1,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.
=(7.8+2.2)+4.56,
=10+4.56,
=14.56;
(2)0.75×6.4-0.75×5.4,
=0.75×(6.4-5.4),
=0.75×1,
=0.75;
(3)78÷0.25÷0.4,
=78÷(0.25×0.4),
=78÷0.1,
=780;
(4)9.9×57,
=(10-0.1)×57,
=10×57-0.1×57,
=570-5.7,
=564.3.解析分析:(1)运用加法交换律简算;
(2)运用乘法分配律简算;
(3)运用除法的性质简算;
(4)把9.9看作10-0.1,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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- 1楼网友:雪起风沙痕
- 2020-07-04 00:23
感谢回答,我学习了
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