4.3 Time  (Page 2/4)

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 $\frac{1}{2}$ min: ......................... .........................

$\frac{3}{4}$ min: ......................... .........................

$\frac{9}{\text{10}}$ min: ......................... .........................

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

1.2 how many minutes there are in:

2 hours:

1 $\frac{1}{2}$ hour:

$\frac{1}{4}$ hour:

3 $\frac{1}{6}$ hour:

a day:

1.3 How many hours there are in:

your school day:

1 week:

1 $\frac{1}{4}$ day:

360 min:

1.4 How many days there are in:

8 weeks:

264 hours:

$\frac{1}{2}$ 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