Microsoft Windows Calculator (CALC.EXE) does not reliably subtract two
numbers with decimal values. This problem occurs in both modes (standard
and scientific) of Calculator.
Calculator does not round the decimal values properly. While Calculator is
determining how to display the solution, it encounters a loss of precision
and shows an incorrect answer.
Microsoft has confirmed this to be a problem in Windows 3.0.
Windows 3.1x, Windows for Workgroups 3.1x
To correct this problem in Windows 3.1x and Windows for Workgroups 3.1x,
obtain the updated CALC.EXE file from the Microsoft Web site.
Steps to Reproduce Problem
- Start Calculator.
- Input the largest number to subtract first (for example, 12.52).
- Press the MINUS SIGN (-) key on the numeric keypad.
- Input the smaller number that is one unit lower in the decimal
portion (for example, 12.51).
- Press the EQUAL SIGN (=) key on the numeric keypad.
Subtracting 12.51 from 12.52 results in one of the following incorrect