Next week the children will be looking at time. In particular, the children will be solving numerous problems involving converting between units of time.
Time is a way of measuring how long something lasts, how long it takes to do something or how long before things start or come to an end.
Here is an example of how time works: we know that the school day starts at 9.00am and will be over at 3.30pm. To put it another way, the school day will be over in six and a half hours.
There are 24 hours in one day, but the day can be measured by splitting it into two halves.
The first 12 hours of the day – from midnight to midday – are called AM, and the next twelve hours – from midday to midnight – are called PM.
When writing down times, morning times end in ‘AM’ and afternoon times end in ‘PM’. This is called analogue time.
AM or PM?
With analogue time, the only way we know the right time of day is by adding AM or PM next to the time so we know if it’s a morning or an afternoon. This is important because there is an ‘AM’ and also a ‘PM’ for every time of the day. For example, at 8.30am you are probably on your way to school, but at 8.30pm you are probably on your way to bed!
Digital time doesn’t break up the 24 hours of a day into two halves, and digital time doesn’t use AM or PM. Instead, it counts each of the 24 hours in the day.
7am is written as 07:00. 12pm (midday) is written as 12:00. In the afternoon, the clock numbers continue to increase, so that 1pm becomes 13:00, and 2pm becomes 14:00, and so on, until 23:59. The clock then resets to 00:00 (midnight), to begin counting the new day.
Digital time is written like a 24-hour timer, so 1.15am becomes 01:15, and 2.45pm becomes 14:45.
Challenge: Can you convert these analogue times into digital times? Remember that a digital clock is like a timer and it just keeps adding an extra hour after 12pm.