The change in the value of an account when given to the nearest dollar

What changes may occur if the given dollar will be rounded off to its nearest value.
There will only be 2 chances, the dollar will become smaller or bigger. Why?
Because in mathematical rules of rounding off numbers:
number below 5 will be round down and 5 and up will be rounded up.
For example:
You have a bill of $6.79  since the number next to the decimal point in the right is 7, it will be rounded up to $7.
But if your bill is $6.25, it will be rounded down to $6.00