Re: Adding two numbers of high precision results in a number of low precision??

*To*: mathgroup at smc.vnet.net*Subject*: [mg56960] Re: Adding two numbers of high precision results in a number of low precision??*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Wed, 11 May 2005 05:24:23 -0400 (EDT)*Organization*: The University of Western Australia*References*: <d5mv2v$dv0$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <d5mv2v$dv0$1 at smc.vnet.net>, Kees van Schaik <schaik at math.uni-frankfurt.de> wrote: > how is it possible that if I add two numbers of precision ca. 390 I get > something of precision 53 back? It is quite easy. For example, try this a = 1`390 b = -1`390 + 10^(-335) Precision[a] Precision[b] Precision[a + b] Cheers, Paul -- Paul Abbott Phone: +61 8 6488 2734 School of Physics, M013 Fax: +61 8 6488 1014 The University of Western Australia (CRICOS Provider No 00126G) AUSTRALIA http://physics.uwa.edu.au/~paul http://InternationalMathematicaSymposium.org/IMS2005/