About Time
Key words: minute, hour, second, analogue, digital
Notes for tutor: add any key words, for time, that are
appropriate to your course.
Purpose: This unit is designed to help tutors who teach courses in which working with
time is important. These courses may involve scheduling of work, calculating with
units of time, and working with international time zones.
Tutor Outcomes:
1. Know the origin of our units of time and understand why these units are difficult
for learners.
2. Present learning opportunities that develop flexible thinking in using units of
time.
Section 1: Mathematical Background
Page 1: Where did the units of time come
from?
The units of time we use for seconds,
minutes and hours came from ancient
Babylonia (present day Iraq).
The Babylonian year was 360 days made up
of 6 months of 60 days. It is not clear why 60
was so popular but it may be that it can be
divided easily into many fractions, e.g. ¼ of
60 is 15.
So that is why there are 60 seconds in a
minute and 60 minutes in an hour.
There are 24 hours in a day and 24 can be
fractioned easily as well!
Section 1: Mathematical Background
Page 2: Why do learners find time challenging?
There are two reasons why measuring time
is challenging.
The first reason is that:
Unlike length, area, and volume it is not physically tangible. Unlike weight and
temperature we cannot trust our senses to measure it.
Like normal air pressure, time is with us all the time so we need to make a
deliberate effort to notice it. Unlike air pressure, we have no way to speed it up or
slow it down (apologies to Einstein).
Time is tied to emotion and perception. Events we do not like seem to take a long
time. Events we like are over way too soon. Three minutes of pain seems much
longer than three minutes of holiday.
Section 1: Mathematical Background
Page 3: The second reason is that
Time is difficult because many of the standard units we choose to measure it with
are based on 12, 24, 60 or 360. This makes it difficult to add and subtract time
using our base ten number system.
For example, suppose a job starts at 10:40am. It is “forty minutes past ten in the
morning” or “twenty to eleven in the morning.”
The job lasts an hour and a half. When will it be finished?
Firstly you need to recognise that one and a half hours is one and a half lots of 60
minutes since there are 60 minutes in an hour. 1½ x 60 = 90 minutes.
Then, you have to add on 90 minutes because you are working with 60 not 100.
+ 20
10:40am
+ 60
11:00am
+ 10
12:00pm
12:10pm
Section 2: Activity
Page 1: Time and language
Brainstorm: Whole class.
Ask learners to think of anything to do with time. May include proverbs and
sayings, and the different ways we record time.
Tutor to record. ( recognising prior knowledge, acknowledges the impact of culture
and work life on how we operate with time and how we think about time).
Discuss responses focusing on the ones that are appropriate for your course .e.g egg
timer for hospitality, 24 hour clock for tourism.
Examples:
Hours, minutes, seconds, digital, analogue, 24 hour, days, months,
years etc.
‘Time and tide waits for no man’.
‘All in good time’.
‘Times up’.
Half time, full time, part time
For the time being
Lets call it a day
No time like the present
Section 2: Activity
Page 2: What aspects of time do your learners need to
know about and be able to use in their course?
Ask learners to discuss and record in pairs, then report
back.
Tutor to record. ( recognising prior knowledge).
If students do not think of things to do with time
management in general or anything else that you
think is relevant, prompt them.
Discuss things like:
•Hours, minutes, seconds, am, pm.
•Specific language of time used in the course. E.g. Part time, full time, time in lieu.
•Specific recording of time. E.g 24 hour clock
•Specific calculations for time. E.g. truck drivers allowing for rest times
•General time applications. E.g time management
Section 2: Activity
Page 3: Building 60 Jigsaw:
Provide each learner with the pieces from the two circles and two strips,
marked in sections (Copy master 1)
The tutor to have the pieces already cut and in sets.
Pose the following problems:
•Using the circle pieces make a clock showing 60 minutes.
•Ask learners to share with a partner what they did and why it makes 60 minutes.
•Ask learners to replicate this with the strips.
Discuss: why do the circle and the strip show the same amount of time?
In pairs use the circle pieces and then the strip pieces (or the other way around) ask
questions such as:
•What would two hours look like?
•What would one and a half hours look like?
•How many fifteen minutes in an hour?
•How many five minutes in an hour?
•Which is bigger three lots of 15 minutes or 45 minutes?
Section 2: Activity
Page 4: What about am and pm?
Discuss the meaning of am and pm. (a is before p in the alphabet therefore am is
the morning, anything that you know that will help the learner remember which is
morning and which is afternoon)
Provide the learners with 2 strips of paper.
Pose the following problems:
•Mark the hours 1 – 12 on each strip. Why 1-12? Discuss.
•Label one strip am and the other pm. Fold to show in analogue. Discuss.
•Put the moon at the top and the sun at the bottom of the am strip. (Copy Master 2
is an example).
•Put the second strip below the first one to show 24 hours and how am and pm
link. Place them in a circle to show a 24 hour day going from midnight to midday
and back to midnight.
•Mark on lunch time, morning tea, when you get up and other times relevant to the
learners.
•Record these times in different formats. E.g 1 o’clock, 1.00am, 1300. Discuss
Section 2: Activity
Page 5: 24 hours – going over midnight
•Tutor to write a time on the board. E.g 6am
•Learners in pairs discuss other ways of recording
this time (analogue, digital, 24 hour)
•Share and discuss as whole group
•Tutor asks learners, ‘what happens when you go over midnight?’
•Discuss
•Learners in pairs
•Each learner writes a time. Learners swap and fill in
as many other ways of recording the time given.
• Discuss answers.
Section 2: Activity
Page 6: Reading time in different formats
Provide learners with different time formats.
Learners in pairs:
•Find 6 o’clock on each format. Ask why? Share and discuss.
•Find 1400 hours on each format. Ask why? Share and discuss.
•Find 2pm on each format.
Ask why? Share and discuss.
Provide learners with copies of time formats specifically used in their course.
Ask similar problems relevant to these time formats
Examples: time sheets, log books, cleaner sign offs, travel times, bus timetables,
nursing charts. Bookings for appointment
Section 2: Activity
Page 7: What time is it?
Recording time:
Time is set out in different formats.
Provide each pair of learners with copy master 3.
Ask them to record the times marked on each diagram.
Tutor: Select one or two of the diagrams and ask for feedback from the learners.
Discuss.
Points arising could be:
•The numbers used in a 24 hour format and what they mean.
•Am and pm
•Hours in a day, minutes in an hour and seconds in a minute.
•The appropriate way to record time in different situations – when would you use
digital or analogue or 24 hour.
Repeat this activity using time formats specifically used in your course.
Section 2: Activity
Page 8: What time is it?
Calculating time using a number line.
Example 1: Refer to slide 4 for adding on time.
Example 2: Working out the difference
You started work at 8:30 or half past eight.
You finished the job at 10:45 or quarter to eleven.
How long did the job take?
Learners need to recognise:
•One hour is one lot of 60 minutes since there are 60 minutes in an hour.
•30 minutes is half an hour and therefore there are two lots of them in an hour.
•15 minutes is a quarter of an hour and therefore there are four lots of them in an
hour.
•you can use partitioning strategies to solve the problem.
8:30am
9:00am
10:00am
+ 60
8:30am
10:30am 10:45am
+ 60
9:30am
+15
10:30am 10:45am
Section 2: Activity
Page 9: Time and fractions
If you're basing time on hours and minutes, the hours would be whole numbers and
the minutes would be fractions. Since there are 60 minutes in an hour, each minute
is 1/60.
Examples: 30 minutes: 30/60 = ½ hour, 15 minutes:
15/60 = ¼ hour
In pairs provide one learner with a clock face and the other with a strip with the
times marked.
•Ask each learner to fold the paper in half. How many minutes in each half? Why
do we say half past ten? What is another way to say half past ten. (30 minutes past
ten or 30 minutes to eleven). Learners discuss the two representations.
•Ask each learner to now fold the paper in half again. What fraction are each of
these pieces? (one quarter) How many minutes in each quarter? How many
minutes in three quarters of an hour? How else do we say this time? Learners
discuss the two representations.
The learner with the clock face may need to think about where to fold. Do you need
to start at 12 o’clock? Discuss.
Section 3: Examples
Page 1: Linking circular and linear pictures of time – minutes in an hour.
Provide each learner with a strip marked in equal sections of five minutes adding up
to an hour.
(Copy master 4)
Pose the following problems and discuss the results as you go:
•Lay the strip out and put a paper clip on 60 minutes.
What is this the same as? Why? (1 hour).
• Now fold the strip to show it in a circle.
•Lay out the strip and use a paper clip to show
30 minutes. What is this the same as? Why?
Now fold the strip to show it in a circle.
•Repeat for other times.
Section 3: Examples
Page 2: Time conversion
Matching activity. Tutor to cut and put into sets.
(Copy master 5, Analogue to digital. Digital to analogue).
•Which of these show the same time and how do you know?
•Ask learners to record times in at least three different ways. E.g analogue, digital,
24 hour, words, using fractions.
Tutor read the times out loud.
Examples:
Two fifteen
A quarter to six
Three twenty six
Fifteen thirty
Eight fifty
Ten to seven
Thirty five minutes to nine
2pm
4am
Seven minutes past one
Section 3: Examples
Page 4: Matching cards
(Copy master 6)
Provide each pair of learners with a set of cards.
Learners are to discuss and put together the matching
cards in groups of….. Why do they match?
Or provide each learner with a set of cards to match
in groups of……. Why do they match?
Or hand out the cards to the whole group. Ask the group
to find everyone who has a card that matches to the
one you have. Why do you match?
Snap – make a set of similar cards to play snap.
Section 4: Assessment
Page 1: An eight hour day:
You are expected to work an eight hour day with half
an hour extra for lunch.
•You start work at 6am what time will it be when
you finish?
•You start work at 8.30am what time will it be when
you finish?
•You start work at 1900 hours what time will it be when you finish?
•You finish your work day at 4.15pm what time did you start?
•You finish your work day at 0705 what time did you start?