It was just a matter of time.

Old Dr Algy B'rah faced the Lower Third maths class for lesson 10 on Friday afternoon.

'Now, today, or perhaps it was yesterday, when I said it would be tomorrow. In fact sometime recently I said that it was about time I spent some time teaching you time.

Time is easy to understand and to help I've brought in a real clock. This is the clock face. You'll see that it doesn't have eyes or a nose but it does have hands. Unlike you there are three hands to one face. The first hand is the hour hand, the second hand is the minute hand and the third hand is the second hand. Is that clear?

The little hand is the hour hand and the big hand is the minute hand. That's minute not mi'nute, otherwise it wouldn't be big would it?

There are numbers round the clock face. They start with 1, which is not the number at the top and go round to 12 which is at the top. This is because there are 24 hours in a day. So there are 24 hours in a day and we put 12 of them on a clock and use them twice.

See all these little marks. They are the marks for minutes which can also be used for seconds and there are 60 of those, so 1 means 1 if it's hours and 5 if it's minutes and 5 if it's seconds and 2 means 10 minutes when it's not hours and 10 seconds when it's not minutes. So there are 60 minutes in an hour and 60 seconds in a minute and we only use them once, not twice like hours.

When the big hand is pointing at 12 and the little hand is pointing at 4 it is four o'clock. No it isn't really 4 o'clock now, sit down, and no, Seamus, o'clock is not an Irish name.

The hands go round and round and round. It is all very logical. It takes the hour hand half a day to go round. It takes the minute hand an hour to go round and it takes the second hand a minute to go round. And when the hour hand has been round twice it's tomorrow and today becomes yesterday.

Now, when we start to go past o'clock, we get to times like 5 past 1, which we write as 1.05. This means the little hand starts to move away from the 1 and the minute hand moves away from the 12. The little hand heads for 2 and the big, minute hand moves away from the 12, which also means zero, but it doesn't say it, and heads for the 1which also means 5. This goes until
30 past 1, which is also half past 1, which is also 1.30, but the. is not a decimal and 30 is not the decimal .30 which is 3/10 but now it's 1/2, not .50 so we have to remember that 1/2 can be written as .30, but if you do that with decimal numbers I will mark it wrong.

Then we say 25 to 2, which is not tutu or to to or two two and 20 to 2 and quarter to 2 and 10 to 2. Of course 20 to 2 could be one third to 2, but that would be difficult so we don't say that, because we want time to be easy. And of course 20 to 2 could be one forty, which is not the same as forty one backwards, because we always say the hour first except when we say it second after the minutes. And the to is not two or 10 to 2 would be 1022 which is forty four years before the Battle of Hastings.

So we count in minutes after the hour, but only until 30 minutes after the hour, then we count down to the next hour, even though the minute hand is now moving up, except when we use times like 1.35. This means we change the hour we are talking about at half past the first hour and use the next hour half an hour before we reach the next hour. Once you think about that it all becomes clear, doesn't it?

Now you have all that clear we can move on to the 24 hour clock which is used for trains, buses and aeroplanes, all examples where you really need to know time to be on time. We still use the 12 hour clock face I've shown you but when we go round the second time with the hour hand we now have to remember that for the 24 hour clock 1 means 13, 2 is 14, 3 is 15 and so on. So the 1 on the clock face can mean 1 for hours, 13 for hours, 5 for minutes and 5 for seconds. When we get past 6 numbers like 9 can mean 9, 21,45 or 1/4 and 7 can mean 7, 19,35 or 25. And don't forget that 10 + 5 = 3 with the 12 hour clock and 10 + 5 = 15 with the 24 hour clock and 23 + 8 = 07 with the 24 hour clock and I know we haven't written 0 in front of a whole number before.

On the 24 hour clock after times like fifteen fifty nine we go to sixteen hundred, which is really fifteen sixty, but after 59 we go back to zero again and call it hundred. This means we have to remember that 20.40 is not the same as 20.40 in decimals but is the same as 8.40 and 20 to 9. That's clear to me, so it should be clear to you.

I just can't understand why you can't do time. No I don't mean "do time" as in "doing time" Bodger.'

And we expect young children to understand time!

Learners who are insecure or uncertain do not handle inconsistencies well. Time is full of inconsistencies, in the vocabulary used and in the way numbers are used.

A new book on time in the ‘What to do when you can’t..’ series will be published soon.