小学数学知识问答300例—精确度
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111.什么叫做精确度?
一个准确值用它的近似数表示时,允许有一定程度的误差,并且误差要根据条件或需要保证必要的精确度,这叫做精确度。例如:圆周率π=3.14159……,用去尾法精确到0.1,0.01,0.001,……的不足近似值为3.1,3.14,3.141,……;用进一法精确到0.1,0.01,0.001,……的过剩近似值是3.2,3.15,3.142,……。这里的0.1,0.01,0.001,……,就表示近似数的精确度。
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