I sussed this in first week I was here. Now I carry toffees and biscuits with me and if the amount I'm due to pay has an odd QR0.25 in it I give THEM a toffee :o)

Actually, in MegaMart at Centre (by Ramada) they just forget about the odd QR0.25 whichever way it goes, so it evens out in the end I guess.