用简便方法计算:31.8*7.9+19*9.25+44.3*2.1
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/28 20:22:42
![用简便方法计算:31.8*7.9+19*9.25+44.3*2.1](/uploads/image/z/69782-14-2.jpg?t=%E7%94%A8%E7%AE%80%E4%BE%BF%E6%96%B9%E6%B3%95%E8%AE%A1%E7%AE%97%EF%BC%9A31.8%2A7.9%2B19%2A9.25%2B44.3%2A2.1)
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用简便方法计算:31.8*7.9+19*9.25+44.3*2.1
用简便方法计算:31.8*7.9+19*9.25+44.3*2.1
用简便方法计算:31.8*7.9+19*9.25+44.3*2.1
原式=31.8*(8-0.1)+(20-1)*9.25+44.3*(2+0.1)
=254.4-3.18+185-9.25+88.6+4.43
=(254.4+185+88.6)-(3.18+9.25-4.43)
=528-8
=520
不知还有没更简单的