Please explain this phenomena of rounding / display issues

This is weird and driving me crazy!!!

Can some PELASE explain this phenomena.

A1 = 122775.54 (even displayed on screen as 122775.54000000000000000000000000000000000)
A2 = 122774.75 (even displaved on screen as 122774.75000000000000000000000000000000000)


A4 = A1-A2


Result, as displayed on screen = 0.789999999993597.
WHAT?? HOW!?

Should simply be 0.79.

All formats are in "General" format. So it is not a display issue. General should display all values.

This is a fairly well known phenomenon associated with the way Excel (and other software) deals with decimals and floating point numbers.

See Chip Pearson's article http://www.cpearson.com/excel/rounding.htm

For your subtraction result you'll need to wrap it in an =ROUND(A1-A2,2) function

Regards