Main content

## 1st grade

### Course: 1st grade > Unit 3

Lesson 3: Time# Telling time (labeled clock)

CCSS.Math:

Sal tells time on a labeled analog clock. Created by Sal Khan.

## Want to join the conversation?

- Why do we have different time lines all over the world?(19 votes)
- The world is round, which means the sun cannot hit all points of the Earth at the same time. When it might be day for you, it is night for somebody on the other side of the Earth, because the sun is unable to reach that point on the planet. Times are adjusted according to where the sun is currently able to light the Earth.(18 votes)

- Why does the 12 on the clock mean12:00and zero minutes?(10 votes)
- Because the12:00shows that the 60 minute cycle is complete and it begins again(8 votes)

- In parallel universe, could there be 100 minutes in an hour instead of 60?(8 votes)
- Certainly, and we could have it in our universe too. For example the french attempted that with French Revolutionary Time.

Copied from Wikipedia: " French Revolutionary Time divided the day into 10 decimal hours, each decimal hour into 100 decimal minutes and each decimal minute into 100 decimal seconds"

They were not the only ones. There have been many such examples throughout history.(12 votes)

- Is there a reason for the one that goes around faster then the other ones?(4 votes)
- yeah because the smaller one counts the hours and the bigger one counts the minutes(12 votes)

- Why does the analog clock have hands but digital clock have no hands.(6 votes)
- Analog clocks use moving hands pointing at fixed numbers to represent hours and minutes in a 12-hour format. Digital clocks show minutes and hours as moving numbers and so no hands are needed to point the numbers out. Digital clocks can also show time in 24-hour format.(7 votes)

- how does the little hand go faster(4 votes)
- because it is designed for minutes which there are 60 of in a hour so when the hour hand is at a new number the minute hand has moved 60 times(7 votes)

- Why do you have to put like for an example2:05why do you need to put a 0 before the five? Could you just do2:50?(5 votes)
- If you put2:50, you mean:
*two hours and FIFTY minutes*

If you put2:05, you mean:*two hours and FIVE minutes*

50 isn't the same thing of 5, so you couldn't(6 votes)

- How do you tell time on a sundial?(5 votes)
- it's like a normal clock face but there is a stick in the middle so that a shadow is cast by the sun as the stick works as an hour hand(4 votes)

- The long Hand points at 2 and the little hand points at 9 so at the clock is9:08AM(4 votes)
- The little hand is the hour, and the long hand is the minute (in multiples of two). So, if the little hand points at 9, we know it's9:00of some sort. Then, you can see that the long hand points at 2, so it has to be a multiple of 5, so 2 * 5 is equal to 10. So the answer is9:10. Remember, you are not sure if it is AM or PM.(7 votes)

- 100 days is equal to how many seconds(4 votes)
- 100 days = 100(days) x 24(hrs per day) x 60(min per hour) x 60(sec per min)

100 days = 100 x 24 x 60 x 60

100 days = 8640000 seconds(5 votes)

## Video transcript

We are asked, what time is it? So we first want to look at the
hour hand, which is a shorter hand here and see
where it is pointing. And it is pointing
right at seven. So we've just crossed
the seventh hour. So the hour is seven. And then we look at the minute
hand, which is the longer hand. And this minute hand is pointing
straight up, right at the 12. So this means the
12, when you think of minutes, that's zero
minutes past the hour. And then each number
represents five more minutes. So this is right at 7:00. Let's check our answer. Let's do a few more of these. Where is the hour hand? So this hour hand,
you might say, hey, this looks closer to
eight than it is to seven, but the key is to realize
that it has passed seven and it hasn't gotten
quite to eight yet. So we're still in
the seventh hour. So the hour is seven. Notice, these hands go
in a clockwise direction. So just past seven hasn't
gotten to eight yet. So the hour is seven. And when we want to think
about the minutes, remember, we start at the top
of the clock, that's zero minutes past the hour. And then we can count
by fives all the way to where the minute hand is. So 0, 5, 10, 15, 20,
25, 30, 35, 40, 45. We're 45 minutes past the hour. So it's 7:45. Let's do a couple more. So where's the hour hand? Well it's between
the one and the two, but the key is to realize
that it's going clockwise, it's passed the one, and
it's about to get to two. So it's still in the first hour. So the hour is still one. And then the minutes, we just
have to count from 0 by fives. So 0, 5, 10, 15, 20,
25, 30, 35, 40, 45. It's 1:45 PM. Let's do one more. So here, once again, hour
hand is between 1 and 2. So it's past one, it
hasn't gotten to two yet. So we're still in
the first hour. And then the minutes,
well, we start at 12. That's zero minutes
past the hour. 0, 5, 10, 15. So it is 1:15. Let's do even one more. So this one the hour
hand is exactly at two. And the minute hand
is exactly at 12. So that means we're zero
minutes past the hour. So it's zero minutes
past the hour.