Its value rests on its monetary use; it is fiduciary money, not commodity money.

It is limited simply by letting "the needs of the people" determine its amount.

This is done by issuing it only in exchange for other money of the larger denominations, and by redeeming it in other money on demand.

Fractional coins are issued on the request of banks in exchange for standard money.

One needing "change" gets it at the bank; when the bank finds its supply falling short it gets more from the government mints.