From: cram on 13 May 2010 13:09 work with Xp and Access2003 I want to do following In an Input form I want to check if some data aore correct. based on invoices I introduce the BasicAmount, the txes and the total of the invoice i.e. the sum of Basic + Taxes say i.e. 100 + 21 = 121 I intorduce the 100, the 21 and the 121. As matter of contol I compare the calculated sum of 100+21 and compare with the inputed 121. If there is a difference I show an error message. My problem is now that for SOME records the message appears although the 3 inputs are correct. As futher detail, all nummers are "single". I'm afraid that in calculating "the sum" there must be some "distorsion" somewhere in the decimal-figures. Any one any idea? -- cram From: KARL DEWEY on 13 May 2010 16:48 You need to show us what your formulas look like. Also post examples of the 'distortion' you are getting, input and output numbers. -- Build a little, test a little. "cram" wrote: > work with Xp and Access2003 > I want to do following > In an Input form I want to check if some data aore correct. based on > invoices I introduce the BasicAmount, the txes and the total of the invoice > i.e. the sum of Basic + Taxes say i.e. 100 + 21 = 121 > I intorduce the 100, the 21 and the 121. As matter of contol I compare the > calculated sum of 100+21 and compare with the inputed 121. If there is a > difference I show an error message. > My problem is now that for SOME records the message appears although the 3 > inputs are correct. > As futher detail, all nummers are "single". > I'm afraid that in calculating "the sum" there must be some "distorsion" > somewhere in the decimal-figures. > Any one any idea? > -- > cram From: John W. Vinson on 13 May 2010 18:46 On Thu, 13 May 2010 10:09:01 -0700, cram wrote: >work with Xp and Access2003 >I want to do following >In an Input form I want to check if some data aore correct. based on >invoices I introduce the BasicAmount, the txes and the total of the invoice >i.e. the sum of Basic + Taxes say i.e. 100 + 21 = 121 >I intorduce the 100, the 21 and the 121. As matter of contol I compare the >calculated sum of 100+21 and compare with the inputed 121. If there is a >difference I show an error message. >My problem is now that for SOME records the message appears although the 3 >inputs are correct. >As futher detail, all nummers are "single". >I'm afraid that in calculating "the sum" there must be some "distorsion" >somewhere in the decimal-figures. >Any one any idea? Since these values refer to money, I'd strongly suggest using the Currency datatype rather than Number... Single. Single numbers are floating point values; as such, some values cannot be represented accurately. 100 and 21 should work, but (for instance) ?csng(3.1) + csng(5.3) - 8.4 9.53674312853536E-08 Single *IS AN APPROXIMATION*, accurate to about 7 decimal places, and as you see, not always exact! Using Currency datatype avoids this issue: ?ccur(3.1) + ccur(5.3) - 8.4 0 -- John W. Vinson [MVP]  |  Pages: 1 Prev: Error MessageNext: Condition navigating between Controls