# Connexions

You are here: Home » Content » Mathematics Grade 5 » Time

### Lenses

What is a lens?

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

#### In these lenses

• GETIntPhaseMaths

This collection is included inLens: Siyavula: Mathematics (Gr. 4-6)
By: Siyavula

Collection Review Status: In Review

Click the "GETIntPhaseMaths" link to see all content selected in this lens.

Click the tag icon to display tags associated with this content.

### Recently Viewed

This feature requires Javascript to be enabled.

### Tags

(What is a tag?)

These tags come from the endorsement, affiliation, and other lenses that include this content.

Inside Collection (Course):

Course by: Siyavula Uploaders. E-mail the author

# Time

Module by: Siyavula Uploaders. E-mail the author

## TIME

Activity 1:

To solve problems that include calculating and converting appropriate time units [LO 4.2]

1. COMPETITION TIME!

In this activity your general knowledge will be tested. Let us see who can answer first – the boys or the girls! Each correct answer is worth 2 points. Points will be subtracted if learners shout out.

1.1 How many months are there in a year?

1.2 Which months have only 30 days?

1.3 Which months have 31 days?

1.4 How many days are there in a year?

1.5 How many days are there in a leap year?

1.6 How many days does February have in a leap year?

1.7 How many days are there in a school week?

1.8 How many seconds are there in a minute?

1.9 How many minutes are there in an hour?

1.10 How many hours are there in a day?

1.11 How many weeks are there in a year?

1.12 How many minutes are there in quarter of an hour?

1.13 How many seconds are there in three-quarters of a minute?

1.14 How many days does December have in a leap year?

Who won?

BRAIN-TEASERS!

• How many years are there in a decade?
• What is a millennium?
• What is another word for a time period of 100 years?
• Some people use v.a.e. and a.e. instead of BC (Before Christ) and AD (Anno Domini). What do they mean?

DID YOU KNOW?

We use the Christian calendar that began with the birth of Jesus. The names of the months originated from Roman times.E.g. August is named after the Roman emperor, Augustus Caesar, who lived form 27 BC to 14 AD.

Activity 2:

To describe and illustrate the way in which time is represented in different cultures [LO 4.4]

1. CHALLENGE: SOME “RESEARCH” FOR YOUR PORTFOLIO!

Let us do some research into how time is indicated in other cultures. Ask your teacher for the paper you will need to work on.

• See whether you can find a Jewish or Muslim calendar.
• Compare it to our calendar and make a list of the differences and similarities.
• Tell your classmates how they differ, and in what way they are similar.
• Give it to your teacher for assessment.
• Exhibit it in the classroom for all to see.
• Remember to file it neatly in your portfolio.

REMEMBER THESE ABBREVIATIONS

seconds : s

minutes : min

hour : h

day : d

week : wk

month : mo

year : a

DID YOU KNOW?

The symbol for hour (h), comes from the Latin word “hora” that means “hour”.

The symbol for year was originally “a”. This comes form the Latin word “annus”, which means “year”.

Activity 3:

To use measuring instruments, including stop-watches, to measure time accurately [LO 4.3]

1. What is a stop-watch?

2. Work together with a friend and complete the table, using a stop-watch.

 Time estimated Time measured Difference 1. Count up to 20 ..................... ..................... ..................... 2. Tie your shoe lace ..................... ..................... ..................... 3. Open and close the classroom window. ..................... ..................... ..................... 4. Write your name and surname. ..................... ..................... ..................... 5. Calculate 468 × 7 ..................... ..................... .....................

Activity 4:

To solve problems that include calculation and conversion of appropriate units of time

[LO 4.2]

1. Work together with a friend and calculate:

1.1 how many seconds there are in:

3 min: ......................... .........................

2 1212 size 12{ { { size 8{1} } over { size 8{2} } } } {} min: ......................... .........................

3434 size 12{ { { size 8{3} } over { size 8{4} } } } {} min: ......................... .........................

910910 size 12{ { { size 8{9} } over { size 8{"10"} } } } {} min: ......................... .........................

1 hour: ......................... .........................

1.2 how many minutes there are in:

2 hours:

1 1212 size 12{ { { size 8{1} } over { size 8{2} } } } {} hour:

1414 size 12{ { { size 8{1} } over { size 8{4} } } } {} hour:

3 1616 size 12{ { { size 8{1} } over { size 8{6} } } } {} hour:

a day:

1.3 How many hours there are in:

1 week:

1 1414 size 12{ { { size 8{1} } over { size 8{4} } } } {} day:

360 min:

1.4 How many days there are in:

8 weeks:

264 hours:

1212 size 12{ { { size 8{1} } over { size 8{2} } } } {} year :

2 leap years

BRAIN-TEASER!

How many years are there in 2 centuries, 9 decades, 72 months and 156 weeks?

LET US LOOK AT WATCHES AND READ TIME!

Did you know?

Galileo, a famous scientist from Italy, studied pendulums. The first clocks were made by using pendulums.

CHALLENGE

Make your own pendulum. Tie a piece of rope to a stone. Tie the end of the rope to a branch of a tree and let the stone swing to and fro.

Take a stop-watch and see how long it takes for the stone to swing to and fro 10 times. ..............................

Shorten the rope and time the 10 swings again. What do you notice? ..............................

Replace the stone with a lighter stone. Take the time for 10 swings again. What do you notice now? ..............................

Activity 5:

To read, say and write analogue, digital and 24 hour time to at least the nearest minute and second [LO 4.1]

It is of the utmost importance that we understand how to read time on the different watches, because time is a major factor in our lives. It determines whether we are on time for appointments or not!

1. LET US HAVE A CLASS DISCUSSION

1.1 What is the difference between an “analogue” watch and a “digital” watch?

1.2 What is the function of the long hand and the short hand of the “analogue” watch?

1.3 When do we use “past” and “to” with the analogue watch?

1.4 What do the first two digits indicate on a digital watch?

1.5 What do the last two digits indicate on a digital watch?

1.6 What do the abbreviations “a.m.” and “p.m.” mean?

Do you still remember?

The international notation for time makes use of the 24 hour clock. We write it in the same way that time is indicated on a digital clock. Remember that there must always be 2 digits before and 2 digits after the colon!

2. Write the following in international time:

2.1 20 minutes before 6 in the morning

2.2 half past 6 in the evening

2.3 quarter to 4 in the afternoon

2.4 midnight

2.5 18 minutes before 3 in the morning

2.6 24 minutes before 9 in the evening

2.7 quarter past 5 in the afternoon

COURSE (LENGTH) OF TIME

REMEMBER!

There is a difference between “time” and “course of time”!

Time: e.g. What is the time? Eight o’clock.

Course of time: how long it takes, e.g. a journey from Cape Town to Worcester takes an hour and a half.

Activity 6:

To solve problems that include selecting, calculating with and converting standard units

[LO 4.6]

1. Split up into groups of three. Ask your teacher for paper to work on and try to find the answers to the following:

• Mvesi leaves by taxi on a visit to his family in Middelburg, Cape. If he departs from Cape Town and arrives in Middelburg at 17:05, how long did the journey take?
• A participant in the Two Oceans marathon sets off at 06:15. It takes him 8 hours and 20 minutes to complete the race. At what time did he stop running?
• Dudu is 11 years and 3 months of age. His father, Mr Sooliman, is 39 years and 11 months old. What is their combined age?
• Mr Katlego worked overseas for 9 months and 2 weeks, while Mrs Solomons toured overseas for 4 months and 3 weeks. What is the difference in time that the two were not in South Africa?

3. Now illustrate on the board one of your calculations to the rest of the class.

4. Have a class discussion on the way in which the above-mentioned problems can be solved successfully.

Activity 7:

To determine the equivalence and validity of different representations of the same problem through comparison and discussion [LO 2.6.3]

1. In the previous activity you had the opportunity of solving problems in a way that made the most sense to you. Now work through the following with a friend and look at the different methods that were used.

The Grade 5’s are planning an outing to a crocodile farm. The buses will arrive at approximately 08:45 and will leave at 13:10. How long will they spend at the farm?

1.1 From 08:45 to 09:00 : 15 min

From 09:00 to 13:00 : 4 hours

From 13:00 to 13:10 : 10 min

Thus: Course of time: 4 h + 15 min + 10 min= 4 h 25 min

1.2 From 08:45 to 13:45 it is 5 hours

This is actually 35 minutes too much.

5 h – 35 min = 4 h 25 min

1.3 I calculate it in this way: 13 h 10 min = 12 h 70 min

− 08 h 45 min − 08 h 45 min

4 h 35 min

2. Whose method do you choose?

Why?

Activity 8:

To solve problems that include selecting, calculating with and converting standard units

[LO 4.6]

1. See whether you can solve the following on your own:

Study the tides in Table Bay.

 Tides in Table bay High tide Today: 06:52 and 19:24 Tomorrow: 07:38 and 20:15 Low tide Today: 00:54 and 12:40 Tomorrow: 01:41 and 13:40

1.1 How many hours and minutes will pass between “today’s” two high tide times?

1.2 How many hours and minutes pass between “tomorrow’s” two low tide times?

2. The taxi’s leave from Cape Town Station every 25 minutes. If the first taxi leaves at 06:15, write down the departure times of the 9 taxis that follow after the first one.

3. Write down the following in international time:

3.1 10 minutes earlier than 08:35 ..................................................

3.2 27 minutes earlier than 17:15 ..................................................

3.3 38 minutes earlier than 22:00 ..................................................

3.4 45 minutes earlier than 04:55 ..................................................

Activity 9:

To determine the equivalence and validity of different representations of the same problem through comparison and discussion [LO 2.6.1]

1. In this activity you will again have the opportunity of trying to find different solutions to the same problem with your friends. Divide into groups of three. Discuss the following problem and solutions (methods) and then explain them to a friend who doesn’t understand as well as you do.

Loretta’s practice times for gymnastics are as follows Monday : 2 hours 40 min Wednesday : 1 hour 55 min Thursday : 3 hours 18 minHow much time does she spend practising altogether?

1.1 2 hours 40 min + 1 hour 55 min + 3 hours 18 min

2 h + 1 h + 3 h = 6 h

40 min + 55 min + 18 min = 113 min

= 1 h 53 min

Thus: 6 h + 1 h + 53 min = 7 h 53 min

1.2 I prefer to write the time below each other:

2 h 40 min

1 h 55 min

3 h 18 min

6 h 113 min

= 6 h + 1 h + 53 min (113 min = 1 h 53 min)

= 7 h 53 min

2. Whose method do you like best?

Why?

Activity 10:

To solve problems that include selecting, calculating with and converting standard units

[LO 4.6]

1. In the previous activities you were exposed to a variety of methods. Now use any method and calculate:

1.1 3 weeks 5 days + 7 weeks 6 days + 9 weeks 2 days

1.2 8 days 17 hours + 5 days 21 hours + 4 days 19 hours

1.3 6 hours 45 min + 3 hours 38 min + 2 hours 54 min

1.4 5 min 29 seconds + 9 min 43 seconds + 4 min 42 seconds

1.5 7 years 9 months + 6 years 8 months + 5 years 11 months

Activity 11:

To determine the equivalence and validity of different representations of the same problem through comparison and discussion [LO 2.6.1]

1. Look at the following problem and then discuss the solutions together as a class. Make sure that you understand each method very well.

Sven has been following the programme “Survivors” on TV and noticed that team A took 4 days 18 hours to cover a certain distance. Team B took 7 days 5 hours to complete the same distance. How much longer did team B take?

1.1 I must calculate 7 days 5 hours – 4 days 18 hours.

4 days 18 hours to 5 days = 6 hours

5 days to 7 days 5 hours = 2 days 5 hours

2 days 5 hours + 6 hours = 2 days 11 hours

1.2 7 days 5 hours – 4 days 18 hours

7 days 5 hours = 6 days 29 hours (1 day = 24 hours)

6 days – 4 days = 2 days

29 hours – 18 hours = 11 hours

The answer is thus 2 days 11 hours

1.3 I answer it in this way:

6 5 + 24 = 29 (1 day = 24 hours) 7 days 5 hours

− 4 days 18 hours

2 days 11 hours (29 – 18)

Which method do you understand the best?

Activity 12:

To solve problems that include selecting, calculating with and converting standard units [LO 4.6]

1. Use all the knowledge that you have gained up to now, choose a method you prefer, and calculate the following:

1.1 19 weeks 3 days - 12 weeks 5 days

1.2 17 days 13 hours - 11 days 19 hours

1.3 9 hours 34 minutes - 3 hours 47 minutes

1.4 15 years 7 months - 9 years 10 months

CHALLENGE!

See if you can get the following information from a library (or perhaps the internet!)

1. How did all the months of the year get their names?(You already know about August).

2. Why does February only have 28 days?

3. Why do some months have 31 days and other months have 30 days?

Make a colourful poster showing the above information and share it with the class.

## Assessment

 LO 4 MeasurementThe learner will be able to use appropriate measuring units, instruments and formulae in a variety of contexts. We know this when the learner: 4.1 reads, tells and writes analogue, digital and 24-hour time to at least the nearest minute and second; 4.2 solves problems involving calculation and conversion between appropriate time units including decades, centuries and millennia; 4.3 uses time-measuring instruments to appropriate levels of precision including watches and stopwatches; 4.4 describes and illustrates ways of representing time in different cultures throughout history; 4.5 estimates, measures, records, compares and orders two-dimensional shapes and three-dimensional objects using S.I. units with appropriate precision for:mass using grams (g) en kilograms (kg); capacity using millimetres (mm), centimetres (cm), metres (m) en kilometres (km); length using. millimetres (mm), centimetres (cm), metres (m) en kilometres (km); 4.6 solves problems involving selecting, calculating with and converting between appropriate S.I. units listed above, integrating appropriate contexts for Technology and Natural Sciences; 4.7 uses appropriate measuring instruments (with understanding of their limitations) to appropriate levels of precision including:bathroom scales, kitchen scales and balances to measure mass; measuring jugs to measure capacity; rulers, metre sticks, tape measures and trundle wheels to measure length.

## Memorandum

ACTIVITY 1

1.

1.1: 12

1.2: April; June; September; November

1.3: January; March; May; July; August; October; December

1.4: 365

1.5: 366

1.6: 29

1.7: 5

1.8: 60

1.9: 60

1.10: 24

1.11: 52

1.12: 15

1.13: 45

1.14: 31

BRAIN-TEASER!

10

1 000 years

century

ACTIVITY 3

1. measures time to one hundredth of a second

ACTIVITY 4

1.

1.1:

180

150

45

54

3 600

1.2

120

90

15

190

1 440

1.3

may differ

168

30

6

1.4

56

11

182 1212 size 12{ { { size 8{1} } over { size 8{2} } } } {}

732

BRAIN-TEASER!

299

ACTIVITY 5

2.1 seven o’clock / 07:00 / 19:00

2.2 20 min. past 3 (p.m.)

2.3 five min. to 7 / 06:55 / 18:55

2.4 10 min. to 9 (a.m.)

2.5 1414 size 12{ { { size 8{1} } over { size 8{4} } } } {} to 5 (a.m)

2.6 half past 7; 19:30; 07:30

3. 3.1: 06:20

3.2: 18:30

3.3: 15:45

3.4: 00:00 / 24:00

3.5: 02:42

3.6: 20:36

3.7: 17:15

ACTIVITY 8

1. 1.1: 19 h 24 min.

- 06 h 52 min.

12 h 32 min.

1.2: 13 h 40 min.

- 01 h 41 min.

11 h 59 min.

2.

06:40; 07:05; 07:30

07:55; 08:20; 08:45

09:10; 09:35; 10:00

3.

3.1: 08:25

3.2: 16:48

3.3: 21:22

3.4: 04:15

ACTIVITY 10

1.

1.1: 19 w 13 d

= 20 w 6 d

1.2: 19 days 9 hours

1.3: 13 hours 17 min.

1.4: 19 min. 54 sec.

1.5: 20 years 4 months

ACTIVITY 12

1.

1.1: 6 weeks 5 days

1.2: 5 days 18 h

1.3: 5 hours 47 min.

1.4: 5 years 9 months

## Content actions

PDF | EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

PDF | EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

#### Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

#### Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks