Learning Resources Big Time Learning 12-Hour Student Clock. Hidden gears maintain correct hour and minute relationships as young learners develop an understanding of time-telling concepts. This teaching time clock is made from durable plastic and has easy-to-read hour and minute markings. Hands are colour-coded to aid the learning of hours and minutes. Clock features removable stand and comes with a helpful teaching guide. Clock measures 13cm. Suitable for ages 5+.