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Q28163: Unexpected PRINT USING ".##" Rounding for .xx5

Article: Q28163
Product(s): See article
Version(s): 6.00 6.00b 7.00 | 6.00 6.00b 7.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | | mspl13_basic
Last Modified: 2-FEB-1990

Problem:

For the following statement

   PRINT USING " ###.##"; .245, .255, .265, .275, .285

the output is as follows

   0.25  0.25  0.26  0.28  0.28

whereas you would expect the following

   0.25  0.26  0.27  0.28  0.29

or with IEEE rounding, you would expect the following:

      0.24  0.26  0.26  0.28  0.28

Response:

The internal representation of the numbers used by BASIC differs
slightly from the decimal numbers typed into the source code.

IEEE floating-point format cannot accurately represent numbers that
are not of the form 1.x to the power of y (where x and y are base 2
numbers). The internal representation will be slightly more or
slightly less than the decimal numbers typed into the source code.

The internal representations are correctly rounded and displayed. This
is not a software problem.

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