That it is not easy to carry and to calculate the revenue-expenditure and the remainder have sometimes caused an error calculation results in a waste of time to do the calculation.
Which it is not easy to carry at all times and to calculate revenue - expenses and balances that are sometimes caused wrong calculation causes time to recalculate again.
It is inconvenient to carry all the time and computation expense and balance has some times the calculated error causes the waste of time that must be calculated again.