Video Transcript
How many times a day does the clock
show the given time?
The clock that the question’s
talking about is shown in the picture. We know that at an o’clock time,
the minute hand points to the number 12, but in this picture it’s pointing to the
number three. It’s moved a quarter of the way
around the clock face. This is a quarter past time. And if we look at the hour hand, we
can see what hour of the day it is. The hour hand is on its way from
the number six to the number seven. We know that at 6 o’clock, it
would’ve been pointing exactly to the number six. And so, we can read this time as
quarter past 6.
Now, our question asks us, “how
many times a day does the clock show this time?” Now, it’s easy to make a mistake
here. We might look at the time and just
say, “Well, there’s only one-quarter past 6 every day.” But let’s use some facts to help
us. Firstly, we know that 24 hours are
the same as one day. When we say a day, we don’t just
mean the daytime when the sun is up; we mean a whole day, for example, Monday or
Tuesday. So this includes the daytime and
the nighttime.
Another fact we can use to help us
here is that the hour hand goes round the clock face once every 12 hours. It doesn’t matter what time of day
it is. It takes 12 hours for it to go all
the way around back to where it was. So if we look at our clock face and
we think that our hour hand is in the exact position for quarter past 6, if 12 hours
go by, it’s going to show quarter past 6 again. But there aren’t 12 hours in a
day. There are 24 hours in a day. This is where we can use a number
fact to help us. We know that 12 plus another 12
make 24.
And so, in a whole day, the hour
hand doesn’t just go once around the clock; it goes twice. This clock is going to show the
time quarter past 6 twice a day, quarter past 6 in the morning and then quarter past
6 in the evening. We know that the hour hand makes
two journeys around the clock face in a day. And you know, it doesn’t really
matter what time this clock shows. The number of times every day that
a clock shows any time is always two.
