[coreutils] "ls -lh" rounds up the size of files instead of rounding half up/down.

[crocket]

There is a file whose size is 42949837312bytes.
It's almost exactly 40.000153064727783GB.
"ls -lh" displays it as 41GB.

It is resulted due to rounding up.

However, rounding half down/up is much more common than rounding up in the real 
world.
When I expect moderate file size approximation, this 1GB difference is not 
ignorable.

Is there any reason for this behavior?
Or is it just a mistake?