1.3.2 The relationship between significant figures and relative errors
The digits of significant figures of an approximation can roughly indicate the magnitude of relative error.For example,the relative error of the approximate value 0.023 7 m is(x is the error of the last digit of the significant figures),the relative error of the approximate value 312.0 cm is 0.x/312.0=x/3 120.Generally speaking,the relative errors of an approximation with one,two,three…digits of significant figures are x/10～x/100,x/100～x/1 000….respectively.Therefore,the number of significant digits indicates the magnitude of the error.(https://www.daowen.com)
(x is the error of the last digit of the significant figures),the relative error of the approximate value 312.0 cm is 0.x/312.0=x/3 120.Generally speaking,the relative errors of an approximation with one,two,three…digits of significant figures are x/10～x/100,x/100～x/1 000….respectively.Therefore,the number of significant digits indicates the magnitude of the error.(https://www.daowen.com)