quad/r/ri four quadrant – open space with buildings on 4 sides; quadrennium – period of 4 years; quadruped – a 4-footed animal.

quart fourth quarter – one fourth; quart – a fourth of a gallon; quartet – a musical composition or group involving 4 voices or instruments.

quin/t five, fifth quintett – a composition for 5 voices or instruments; quintessence – pure essence, based on the ancient philosophy that there was a fifth element that was present in all things; quintuple – fivefold.