NeoCal for Pocket PC User Guide
Pressing any digit, the decimal point, or the exponent button causes the calculator to go into a special mode for entering numbers. The display format is not used; rather, the buttons pressed to enter the number are displayed. The rightmost character in the display gets erased when the button is pressed.
When entering negative numbers, first enter the digits for the number, then press the button. If you press the button first, it will change the sign of the number currently being displayed, not the number you're about to enter.
When entering numbers in exponential format, first enter the mantissa, then press , and then enter the exponent. If the number is negative, press before pressing . If the exponent is negative, press after pressing .
If the button is pressed while you're not entering a number, it will have the same effect as pressing or . If the button is pressed after a prefix key, the prefix is cancelled.
Pressing any key to perform an operation will terminate the "entering a number" mode and the display will be formatted using the display settings.