Mathematical
Literacy
NQF 4
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Mathematical Literacy Level 4 Module 2
Level 4 Mathematical Literacy study guide, 86 pages. Read online or get the free PDF download.
Subject: Mathematical LiteracyMultiple grades86 pages
Mathematical Literacy. Study guide, 86 pages. Read online or download the PDF.
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Solving problems with
time, conversions, rate,
ratio and proportion
Module 2
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Overview
2.1 Time, time-of-day formats, elapsed time,
calendars and timetables
2.2 Measurement conversions
2.3 Solving problems involving different time zones
2.3 Performing workplace-related calculations
involving ratios
2.3 Calculations involving proportion
2.3 Perform workplace-related calculations
involving rates
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Time, time-of-day formats, elapsed
time, calendars and timetables
Unit 2.1
Analogue time
Analogue clocks use a mechanical method to keep
time.
Digital time
Digital clocks usually show 24 hours.
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Time, time-of-day formats, elapsed
time, calendars and timetables
Unit 2.1
Analogue time
Analogue clocks show 12 hours on their faces and
represent time by the position of hands on the dial.
Digital time
Digital clocks use electronic methods to keep time.
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Time, time-of-day formats, elapsed
time, calendars and timetables
Unit 2.1
Analogue time
The 24-hour day is divided into two periods of twelve hours:
• Before noon: the morning, from 12 a.m. to 11.59 a.m.
• After noon: the time from 12 p.m. to 11.59 p.m.
Digital time
24-hour time does not use a.m. and p.m.
• The times go from 0:00 to 23:59.
• The time 24:00 is the same as 0:00 (midnight).
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Recording times in minutes,
seconds
Unit 2.1
and milliseconds
• Stopwatches are convenient digital handheld instruments.
• Timing starts at the press of a button, and stops when the button is
pressed again. The elapsed time is shown on the screen. Another press
resets the stopwatch to zero.
• Watches and cell phones often have stopwatches built into them.
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Recording times in minutes,
seconds
Unit 2.1
and milliseconds
• The stopwatch in the picture here
recorded 12:38,56.
• The minutes and the seconds are
not decimal, because
1 minute = 60 seconds.
• Milliseconds are decimal.
1 second = 1 000 milliseconds.
• Example:
25 mins, 4 secs and 163 millisecs
= 25 mins 4,163 secs
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Did you know?
Unit 2.1
Accurate timing of sports events is very important.
The finishing times of sprint athletes can differ by only a few
hundredths of a second.
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Did you know?
Unit 2.1
In international sporting events:
• A loudspeaker behind each runner gives the starting signal. This is
because sound takes time to travel and if an athlete is further from
the starting pistol, the tiny time difference could make the
difference between winning and losing the race.
• A special camera detects when an athlete passes the finish line
and shows the exact time.
• Stopwatches are not used because the time it takes to press the
stop button also makes the result inaccurate.
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Calendars
Unit 2.1
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Calendars
Unit 2.1
• There are 365 days in a calendar year, except every fourth year, which is
a leap year with 366 days.
• The years 2008, 2012, 2016 and 2020 are all leap years.
• There are 52 complete 7-day weeks in each calendar year, with 1 day
left over (or 2 in a leap year).
• The year is divided into 12 months. Each month has 30 or 31 days,
except for February, which has 28 days (or 29 days in a leap year).
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Conversions
Unit 2.1
1 000 milliseconds = 1 second
1 minute = 60 seconds
1 hour = 60 minutes = 3 600 seconds
1 day = 24 hours
1 week = 7 days
1 year is about 52 weeks
1 year = 365 days (for the Earth to travel once around the Sun)
10 years = 1 decade
10 decades = 1 century = 100 years
1 000 years = 1 millennium (plural of “millennium” is “millennia”)
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Exercise 2.1
Unit 2.1
Complete Exercise 2.1 on page 38 of your Student’s Book
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Calculating duration
Unit 2.1
• When you calculate how long something takes, you need to add or
subtract with hours, minutes and seconds.
• Calculators use the decimal system, so remember to multiply or divide
by 60 to get decimal answers.
> Example 2.1 page 39
1. Thabo leaves home at 05:25 and gets to his destination
at 11:40. How long did his trip take?
• 05:25 to 06:00 is 35 mins, 06:00 to 11:00 = 4 hrs, 11:00
to 11:40 = 40 mins
• 35 + 40 = 75 mins = 1 h 15 min
• 4 h + 1 h 15 min = 5 h 15 min
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Example 2.1 page 39
Unit 2.1
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Exercise 2.2
Unit 2.1
Complete Exercise 2.2 on page 40 of your Student’s Book
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Time management tools
Unit 2.1
• Timetables and schedules can be used to list tasks, allocate time to
tasks and sequence tasks.
• Schedules may be worked out backwards, from the expected delivered
date, or forwards, working out how long each stage will take from the
time when production can start.
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Time management tools
Unit 2.1
Examples:
• Public information boards used for hours of operation of businesses
and government offices, airline timetables, train schedules, bus
schedules, television programming, concerts and sporting events
• A workplace schedule to list the work hours for employees and the
operating hours for the public
• Project management scheduling as the first step of a project such as
constructing a building, developing a product or planning an
entertainment event.
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Time management tools
Unit 2.1
1. List the tasks accurately, with detail.
2. Estimate how much time is needed for each task. Rather
allow more time than less.
3. Determine how much time is available.
4. Allocate time to your earliest deadlines first, but don’t
neglect the later ones.
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Exercise 2.3
Unit 2.1
Complete Exercise 2.3 on page 43 of your Student’s Book
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Tide timetables
Unit 2.1
Tides
The daily changes in the water levels of the ocean
Tides timetables ”
This table shows the times when the tides will be high and low.
”
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Tide timetables
Unit 2.1
Tide timetables are useful for:
Calculating when it is best to sail a boat into shallow ports or
under bridges.
Planning coastal construction projects.
Disaster clean-ups, e.g. an oil spill disaster
Recreation, e.g. swimmers, hikers crossing rivers, surfers looking
for big waves. Fishermen use information about the tides to
improve their catches because certain species of fish gather
during periods of high or low water.
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Exercise 2.4
Unit 2.1
Complete Exercise 2.4 on page 46 of your Student’s Book
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Measurement conversions
Unit 2.2
To convert from one unit of measurement to another:
Decide whether you are converting to a
bigger unit or a smaller unit.
÷ x
Converting to a Converting to a
bigger smaller
unit, your unit, your
measurement will be measurement will be
smaller, so you will bigger, so you will
divide. multiply.
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Measurement conversions
Unit 2.2
Units of length
10 mm = 1 cm 100 cm = 1 m 1 000 m = 1 km
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Measurement conversions
Unit 2.2
Units of volume or capacity
1 000 ml = 1 ℓ 1 000 ℓ in 1 kℓ
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Measurement conversions
Unit 2.2
Units of mass
1 000 mg
1 in
0001 g
ml = 1 ℓ 1 000 g in 1 kg1 0001ℓ in
0001kg
kℓin 1 tonne
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Exercise 2.5
Unit 2.2
Complete Exercise 2.5 on page 47 of your Student’s Book
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Using given conversion factors
and
Unit 2.2
tables
Cooking conversions:
• 1 teaspoon (tsp) = 5 millilitres (ml)
• 1 tablespoon (Tbsp) = 15 millilitres (ml)
• 1 cup = 250 millilitres (ml)
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Example 2.4 page 48
Unit 2.2
Write all the measurements in this scone recipe in millilitres:
• 2 cups sifted flour
• ½ tsp salt
• 4 tsp baking powder
• 2 Tbsp margarine
• ¾ cup milk
• 2 cups of flour = 2 × 250 ml = 500 ml
• ½ tsp salt = ½ × 5 ml = 2,5 ml
• 4 tsp baking powder = 4 × 5 ml = 20 ml
• 2 Tbsp margarine = 2 × 15 ml = 30 ml
• ¾ cup milk = ¾ × 250 ml = 187,5 ml
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Metric and imperial conversions
Unit 2.2
Although the imperial measurement system is not used in South Africa, you will see
these units as they are often used in the United States and in some other countries.
Length
1 inch (in) = 2,54 cm
1 foot (ft) = 12 inches = 30,5 cm
1 yard (yd) = 36 inches = 91,5 cm
1 mile (mi) = 1 760 yards = 1,6 km
Volume and capacity
1 fluid ounce = 26 ml
1 pint = 20 fluid ounces = 590 ml
1 gallon = 4,5 litres (Imperial) = 3,8 litres (USA)
Mass
1 ounce (oz) = 25 grams (g)
1 pound (lb) = 16 ounces (oz) = 450 grams (g)
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Example 2.5 page 49
Unit 2.2
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Exercise 2.6
Unit 2.2
Complete Exercise 2.6 on page 49 of your Student’s Book
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Solid and liquid conversions
Unit 2.2
Solid volumes are usually given in cubic units and liquid volumes in
ml, ℓ or kl.
• 1 g of pure water has a volume of 1 ml
• 1 kg of water has a volume of 1 litre
You can use this as an approximation for some other liquids.
• 1 000 mm3 = 1 mℓ
• 1 cm3 = 1 mℓ
• 1 000 cm3 = 1 ℓ
• 1 m3 = 1 kℓ
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Example 2.6 page 50
Unit 2.2
1. A container in the shape of a rectangular prism has the
dimensions: 7,5 cm × 10 cm × 3 cm.
How much water can it hold?
1. 7,5 × 10 × 3 = 225 cm3
It can hold 225 ml of water.
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Area and volume conversions
Unit 2.2
10 mm
10 mm = 1 cm
• Area: 10 mm × 10 mm in a square of 1 cm2.
So there are 100 one mm squares in 1 cm2.
• The conversion factor between mm2 and cm2 is 100.
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Area and volume conversions
Unit 2.2
10 mm
• Volume: 10 mm × 10 mm × 10 mm in a block of 1 cm3.
So there are 1 000 one mm blocks in 1 cm3.
• The conversion factor between mm3 and cm3 is 1 000.
• The conversion factor between cm3 and m3 is 1 000 000.
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Area conversions
Unit 2.2
Units of area
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Volume conversions
Unit 2.2
Units of volume
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Example 2.7 page 51
Unit 2.2
1. Calculate the volume (in cm3) enclosed by a box with a
base size of 5 cm by 25 cm, and a height of 10 cm.
2. Convert this measurement into millilitres (mℓ).
3. Convert this measurement into litres (ℓ).
1. 5 × 25 × 10 = 1 250 cm3
2. 1 250 mℓ
3. 1,25 ℓ
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Temperature conversions
Unit 3.2
There are two main temperature scales:
• °F, the Fahrenheit scale (used in America)
• °C, the Celsius scale (part of the metric system)
• The boiling point of water is 100°C and 212°F.
• When water freezes, it measures 0°C but 32°F.
• So the difference between freezing and boiling point
is 100 degrees in Celsius, but 180 degrees in Fahrenheit.
• To convert, use the formulae:
°C = (°F − 32°) ÷ 1,8 (to find the temperature in degrees Celsius)
°F = (°C × 1,8) + 32 (to find the temperature in degrees Fahrenheit)
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Temperature conversions
Unit 3.2
There are two main temperature scales:
• °F, the Fahrenheit scale (used in America)
• °C, the Celsius scale (part of the metric system)
• The boiling point of water is 100°C and 212°F.
• When water freezes, it measures 0°C but 32°F.
• So the difference between freezing and boiling point
is 100 degrees in Celsius, but 180 degrees in Fahrenheit.
To convert, use the formulae:
°C = (°F − 32°) ÷ 1,8
(to find the temperature in degrees Celsius)
°F = (°C × 1,8) + 32
(to find the temperature in degrees Fahrenheit)
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Example 2.8 page 52
Unit 2.2
When Bongi leaves New York, it is 104°F. It is 8°C when she
arrives early the next morning in South Africa.
a) What was the New York temperature in degrees
Celsius?
b) What was the temperature in South Africa in degrees
Fahrenheit?
a) Use the formula
°C = (°F − 32) ÷ 1,8
°C = (104 – 32) ÷ 1,8
= 72 ÷ 1,8
= 40°C
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Example 2.8 page 52
Unit 2.2
When Bongi leaves New York, it is 104°F. It is 8°C when she
arrives early the next morning in South Africa.
a) What was the New York temperature in degrees
Celsius?
b) What was the temperature in South Africa in degrees
Fahrenheit?
b) Use the formula
°F = (°C × 1,8) + 32
°F = (8 × 1,8) + 32
= 14,4 + 32
= 46,4°F
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Exercise 2.7
Unit 2.2
Complete Exercise 2.7 on page 52 of your Student’s Book
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Solving problems involving
different
Unit 2.3
time zones
• When the sun is high in the sky in one part of the world, it is completely
dark on the other side.
• The Earth rotates so that the sun appears to move from the east to the
west, rising in the east and setting in the west.
• The world is divided into time zones, so that the sun will be at its
highest point at approximately twelve noon wherever you are in the
world.
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Solving problems involving
different
Unit 2.3
time zones
• Countries choose their time zones, so the zones often follow the
borders of countries rather than following a strict vertical line. Some
countries, such as South Africa, India and China, have chosen a single
time zone, while others have multiple time zones.
• In the past, time zones used Greenwich Mean Time as a reference time.
The system is now called Coordinated Universal Time (UTC).
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Solving problems involving
different
Unit 2.3
time zones
• The times to the west are calculated by subtracting hours from UTC time.
• The times to the east are calculated by adding hours to UTC time.
• South Africa is at UTC +2, so the time is always 2 hours later than UTC.
• India is UTC +5½, so it is 5½ hours later than UTC.
• Argentina is UTC –3, so the time is three hours earlier than UTC.
• There are 24 hours in a day, so there are 24 time zones.
• Any place in the same time zone has the same clock time.
• When you move from one time zone to the next one in an easterly
direction, you need to change your clock one hour forwards.
• If you move in a westerly direction you move it one hour backwards.
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Example 2.9 page 53
Unit 2.3
Use the map showing the time zones on the next slide.
1. If it is midnight at UTC, what time will it be at:
a) UTC +2 b) UTC –5 c) UTC +9
2. How many time zones are there in:
a) South America b) Africa?
3. Why do you think most of Europe is on one time zone?
1. a) 2 o’ clock (in the early morning)
b) 7 o’clock (in the evening)
c) 9 o’clock (in the morning)
2. a) 3 time zones
b) 4 time zones
3. Most of Europe is in the European Union (EU) and one
time zone makes business and travel easier.
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Example 2.9 page 53
Unit 2.3
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Daylight saving time
Unit 2.3
• Many countries use daylight saving time.
• In summer, they officially set their clocks one hour ahead of local
standard time. This allows people to do all their activities an hour
earlier, which gives more daylight in the evenings.
• South Africa does not do this.
• Countries including USA, Great Britain and Europe use daylight saving.
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Example 2.10 page 55
Unit 2.3
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Exercise 2.8
Unit 2.3
Complete Exercise 2.8 on page 55 of your Student’s Book
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Performing workplace-related
calculations
Unit 2.4
involving ratios
• Ratios and proportions are used in activities such as mixing ingredients
and using scale drawings and maps.
• Ratio, proportion, rate and percentage all describe the relationship
between two quantities, but don’t give you the actual numbers
involved.
• The statement ‘20% of the residents have been victims of crime’ tells
you the percentage of residents, but does not give you the actual
number of people.
• Percentages tell you a fixed relationship between numbers, which can
help you to solve problems.
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Performing workplace-related
calculations
Unit 2.4
involving ratios
Example
‘20% of the residents have been victims of crime’
• If there are 3 000 residents, then there are
20% × 3 000 = 600 people
who have been victims of crime in that area.
• If there are 10 000 residents, then 20% × 10 000 = 2 000 people
have been victims of crime.
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Ratios and different forms of
ratio
Unit 2.4
Ratio
A ratio is a comparison of two or more numbers. We write the
numbers with a colon (:) between them.
”
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Ratios and different forms of
ratio
Unit 2.4
Example
• If there are 8 students who travel by bus and 12 students who
travel by taxi in one class, then we say we have a ratio of 8 to 12.
• We can write this as 8 : 12.
• Note that 8 : 12 is not the same as 12 : 8.
• Ratios are written without units because the units on both sides
are exactly the same.
• A scale ratio on a map refers to measurement units.
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Example 2.12 on page 58
Unit 2.4
Jabulani is a baker. He knows that biscuits always have the
ratio of 3 : 2 : 1 for flour to butter to sugar. He needs to make
as many biscuits as possible, and he has 4 cups of butter
available. How much will he need of the other two
ingredients?
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Find missing numbers in a ratio
Unit 2.4
Example
We need to use two red tiles for every five blue tiles to make a
certain mosaic pattern. This is a ratio of 2 : 5.
We have 300 red tiles. How many blue tiles do we need?
Solution:
• We need to find the unknown part of the ratio:
2 red tiles : 5 blue tiles
300 red tiles : ? blue tiles
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Find missing numbers in a ratio
Unit 2.4
Example
• Step 1: Find the total number of parts.
The ratio 2 : 5 has 7 parts.
• Step 2: How many in one part.
300 ÷ 2 = 150, so 1 part has 150 tiles.
• Step 3: Multiply the answer by the ratio parts.
150 × 2 = 300 (already known)
150 × 5 = 750
• Step 4: Write down the answer.
The answer is 750 blue tiles.
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Simplifying and comparing ratios
Unit 2.4
1. Can both numbers be divided by a common
factor?
2. As with fractions, whatever you do to one
number, you must also do to the other number
so that the value remains the same.
3. To compare ratios, we write them as fractions.
If the fractions are equivalent, then the ratios
are equal.
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Example 2.13 page 58
Unit 2.4
1. b) Write the following ratios in simplest form: 20 : 35
2. a) Are the ratios 2 : 5 and 12 : 16 equal?
1. b) 20 : 35 Divide both sides by 5.
4:7
1. a) 2 : 5 and 12 : 16 Write both ratios in their
2 : 5 and 3 : 4 simplest form.
No, these ratios are not equal.
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Share an amount in a given ratio
Unit 2.4
Example
Share 1 500 bricks in the ratio 1 : 2.
• Number of parts is 3.
• Divide total amount by number of parts
1 500 ÷ 3 = 500.
• Multiply the answer by the ratio parts:
500 × 1 = 500
500 × 2 = 1 000
• The answer is 500 bricks and 1 000 bricks.
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Example 2.14 page 59
Unit 2.4
• How many millilitres of herbal extracts and syrup will a
pharmacist need to make 300 ml of a cough mixture if
she mixes herbal extracts and syrup in a ratio of 1 : 5?
• There are 1 + 5 = 6 parts altogether.
• Divide 300 ml by 6 = 50 ml.
• Multiply to find each part:
1 × 50 ml = 100 ml of herbal extracts
5 × 50 ml = 250 ml of syrup.
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Exercise 2.9
Unit 2.4
Complete Exercise 2.9 on page 59 of your Student’s Book
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Calculations involving proportion
Unit 2.5
Proportion
Proportion is an equation of two ratios or a statement that two
ratios are equal.
Examples:
• Chefs need to scale recipes up or scale down using proportion.
”
• Cleaners may dilute a cleaning fluid in a 1 : 8 ratio and use proportion
to make the correct volume.
• The number of builders needed to complete a job is inversely
proportional to the length of time the job takes.
• It is also possible to have two ratios that are in inverse proportion or
indirect proportion to each other.
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Direct proportion
Unit 2.5
Definition
Two variables are directly proportional to each other if, as one
variable increases, the other increases in the same proportion.
• If one value doubles, the other one also doubles
• If one variable increases by 3 times, the other one also
increases by 3 times.
• If one variable decreases, the other variable also decreases in
the same proportion.
”
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Example 2.15 on page 61
Unit 2.5
The cost of petrol is directly proportional to the amount of
petrol purchased. If Bontle fills her car’s tank by
purchasing 40 ℓ of petrol for R582, we can use this to
calculate the cost of any other amount of petrol.
Set up a proportion and calculate the cost of:
a) 100 litres of petrol
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Example 2.15 on page 61
Unit 2.5
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Inverse proportion
Unit 2.5
Definition
When two values are inversely proportional to each other, as one
value increases, the other decreases in the same proportion.
• If one value doubles, the other value halves.
• It takes 10 students 4 hours to carry boxes of books into the
college, but it takes 20 students only 2 hours.
• The number of students and the time taken are in inverse
proportion to each other.
• Since the ratio is ‘the other way round’, the fraction is written
‘the other way round’, or inverted.
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Example 2.16 page 62
Unit 2.5
1. A farmer ploughs his land in 6 days using 5 tractors.
How many days will it take to plough the same area
with 3 tractors?
• Write a proportion using x as the unknown:
5 tractors x days
=
3 tractors 6 days
• Note: the second fraction is inverted.
• Solve the equation by cross-multiplying:
5×6=3×x
x = 30 ÷ 3 = 10 days
If he uses 3 tractors, it will take 10 days.
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Exercise 2.10
Unit 2.5
Complete Exercise 2.10 on page 62 of your Student’s Book
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Perform workplace-related
calculations
Unit 2.6
involving rates
Rate
A rate is a type of ratio, used in everyday situations.
• Speed in km per hour
”
• Cost per unit in rands per kilogram
• Amount of medicine per millilitre
• Cost rates of water and electricity services in rands per unit
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Perform workplace-related
calculations
Unit 2.6
involving rates
• The word ‘per’ shows that you are dealing with a rate.
We can also write R15 per litre as R15/ℓ.
• When you solve a rate problem you set up a formula to relate the
quantities.
Example
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Steps to solve a rate problem
Unit 2.6
Step 1:
There are always three quantities in a rates
problem, so there are three different formulae that
you could use. Write them all down.
Step 2:
Read the problem carefully and choose the correct
formula.
Step 3:
Substitute into the formula, making sure that you
are using the correct units. Do the calculation.
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Maths Lit NQF Level 4
Example 2.17 on page 63
Unit 2.6
1. Ayanda runs a race at a speed of 12 km/h.
a) How long will it take her to run 15 km, if she
keeps running at this speed? Write the time in
hours and minutes.
b) How long will she take to run 20 km at this
speed? Write the time in hours and minutes.
c) If she runs for 30 min, how many kilometres will
she run?
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Maths Lit NQF Level 4
Example 2.17 on page 63
Unit 2.5
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Maths Lit NQF Level 4
Example 2.17 on page 63
Unit 2.5
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Maths Lit NQF Level 4
Exercise 2.11
Unit 2.6
Complete Exercise 2.11 on page 64 of your Student’s Book
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Maths Lit NQF Level 4
Finding the best value for money
Unit 2.6
• You can compare different food items to make sure you are getting the
best deal.
• To find out which size is better value for money, calculate the unit price
for the product, e.g. the price per kilogram.
• Then you can compare which is cheaper for the unit price, and thus
better value for money.
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Maths Lit NQF Level 4
Example 2.18 page 66
Unit 2.6
1. A shop advertises two different types of minced meat.
Brand A of minced meat costs R55,95 for 4 kg.
Brand B costs R66,80 for 5 kg.
Which is better value for money?
1. Find the unit price (for one kilogram) for each brand of
mince meat.
Brand A: R55,95 ÷ 4 kg = R13,99/kg
Brand B: R66,80 ÷ 5 kg = R13,36/kg
Brand B mince meat is slightly cheaper per kilogram.
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Maths Lit NQF Level 4
Exercise 2.12
Unit 2.6
Complete Exercise 2.12 on page 66 of your Student’s Book
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Maths Lit NQF Level 4
VIDEO: Application in the
Workplace
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Maths Lit NQF Level 4
Module assessment
Module 2
Complete Module assessment on page 69 of your Student’s Book
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Maths Lit NQF Level 4
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