Odd answer to calculation

[Tony Williams]

Why does the answer to this calculated control sometimes say 3.6E-12 or
7E-12?
=NZ([text195],0)-Nz([Sum of txtIndClientsTota],0)
Thanks
Tony

 

[Douglas J Steele]

That's how floating point numbers work on computers.

Just as we can't represent certain numbers precisely in decimals (think 1/3
or 1/7, for example), so too are there numbers that computers can't
represent exactly. Presumably [Sum of txtIndClientsTota] represents the
result of adding together a number of rows in a table, so there's bound to
be some round-off error. 3.6E-12 is actually 0.0000000000036, so your values
are the same for all intents and purposes.

 

[Joan Wild]

Because the control isn't wide enough to show the answer - so it uses
scientific notation.

 

[Tony Williams]

Thanks very much for the answers, I now understand.
Cheers
Tony