This 11-plus Maths quiz about time is going to look at the 24 hour clock. This clock is used extensively, for example: in computers, in the military and in transport.
Using the 24 hour clock removes all possibility of making a mistake with the time, for example: 'Meet me at 6 o'clock'. Is that 6 o'clock in the morning or in the evening? The use of 'am' and 'pm' doesn't always help because not all people know what they mean: pm = post meridiem = between 12 noon and 12 midnight; am = ante meridiem = between 12 midnight and 12 noon.
Some adults find the 24 hour clock difficult to remember. 16:18 is not as easy as nearly twenty past four, is it? It is a useful thing to learn and you should find it easier than adults. Why? Because you have grown up with computers which always show the time in 24 hours.