To do this you can use the 24-hour clock. The 24-hour clock always uses 4 digits. You see this most often on digital clocks. Complete this interactive activity to understand the 12 and 24-hour clock.

The 24 Hours exhibition at Milan design week features 24 weird and wonderful clocks, all by different designers. We look at seven of the most imaginative examples. On show at Riviera, 24 Hours was ...