THEORY OF APPROXIMATION. 



481 



Arithmetic of Approximate Quantities, 



trP*t ^ J 11 *** 11 '* ^11 the quantities which we 



treat in physical and social science are approximate on]? 

 it seems desirable that attention should^ mid in the' 

 teachmg of arithmetic to the correct interpretation and 

 treatment of approximate numerical statements. We seem 

 to need notation for expressing the approximated S 

 exactness of decimal numbers* The fraction^ 025 * 



small cipher or circle should be added to indicate that 

 there is nothing more to come, as in '0250. Wh en he 

 first figure of the decimals rejected is 5 or more the first 

 figure retained should be raised by a unit, accord n" to a 

 rule approved by De Morgan, and now generally ?ecoa 

 ST '^ *? ^^ that the fraction tllus Detained is 2e" 



^ t , hfractlon " les than the truth, two dots 





oi the approximate numbers 3470 ^2-60^ SOT i^ ^ 

 ' Sandeman, Pelicotetws, p. 214 



I I 



