Rounding Gain Account or Rounding loss a/c

When a bill is paid a batch is usually generated which reduces the vendors balance and cash account. However, when the same bill is paid in foreign currency additional accounts called rounding off gain/loss account and realized gain/loss account arises. What should be the ideal scenario in the system if for a prepayment, the payable control account is debited with amount almost equals to the one crediting rounding off gain/loss account and after reversal of this transaction the rounding off gain/loss account disappears?