Strange Decimal Values? Rounding Error?

[NicholasL]

So I'm having this strange problem. In the picture you should see a small table 3x4 in size. Each value in column 1 is multiplied by 2. Column 2 is multiplied by 5, column 3 is multiplied by 10 and column 4 is multiplied by 0.

So when I multiply .4 by 2...I expect .8 and not .800001
Now, this doesn't make much of a difference but I'd prefer it to not do that.

Likewise when I multiply .9 by 10, I'd like to get 9. While this is very close to 9, I'm not sure why this is happening.
I looked through preferences and found no obvious answer.

What's going on?
Thanks.


Screen Shot 2013-06-20 at 12.51.12 PM.pngScreen Shot 2013-06-20 at 12.52.27 PM.png

[shg]

The binary floating point format your computer uses can't store most base 10 decimals exactly, so errors accumulate. Use ROUND().