Yes I know the groat was four pence (old money) and the guinea was twenty-one shillings but as currency in today's world, they no longer exist in coin form. Same as the farthing and the half-penny and the half-p piece. Likewise the three-penny bit - all gone and now only seen in collectors books. What about the ten-bob note? As far as I am concerned, the sooner we are part of the larger unit, the better for business not to mention the ease of travel etc.