Chapter 1. Getting Started: Numbers in Everyday Life FREE
Every day in South Africa you are surrounded by numbers. A taxi from Soweto to the Johannesburg CBD might cost R22. A 2 litre bottle of milk at Shoprite is marked R34,99. A road sign on the N1 tells you Cape Town is 1 398 km away, and the Springboks won a Test 27 to 13. Mathematical Literacy is the skill of reading these numbers, understanding what they mean, and using them to make good decisions in real life. This first chapter builds your number sense so that the rest of the year makes sense.
1.1 The number systems we use
In everyday life we work mostly with a few familiar kinds of numbers. Whole numbers (also called counting numbers) are numbers like 0, 1, 2, 3 and so on, with no fraction or decimal part. We use them to count people in a class or taxis in a rank. Integers include the whole numbers and their negatives, such as -3, -2, -1, 0, 1, 2, 3. Negative integers appear when a temperature in Sutherland drops to -6 degrees Celsius on a winter night, or when a bank balance is overdrawn by R150 and shown as -R150.
Not all quantities are whole. Fractions describe parts of a whole, such as half a loaf of bread written as \( \tfrac{1}{2} \), and decimals describe parts using place value after a comma, such as R34,99. In South Africa we use the comma as the decimal separator, so two rand and fifty cents is written R2,50 and not R2,50.
1.2 Place value and how big numbers are written
The position of a digit gives it its value. In the number 1 398, the 1 means one thousand, the 3 means three hundred, the 9 means ninety, and the 8 means eight. South African convention uses a space as the thousands separator for large numbers, so we write 1 398 km, 25 000 people at a stadium, or a salary of R18 500 per month. Reading place value correctly stops costly mistakes: R150 000 (one hundred and fifty thousand rand) is very different from R15 000.
Two hundred and forty-three thousand is 243 000. Six hundred and seven is 607. Putting them together: \( 243\,607 \). So the answer is 243 607.
1.3 Reading numbers in real contexts
Numbers carry different meanings depending on where you see them. The same digits can be a price, a measurement, a quantity, or a code. Being a careful reader means asking what the number is counting or measuring, and what unit goes with it.
- Money: a till slip shows R134,75. The R is rand and the digits after the comma are cents.
- Measurement: a bag of mealie meal is 2,5 kg; a Coke is 500 ml; a trip is 320 km.
- Quantity: a Grade 10 class has 38 learners; a 6-pack has 6 cans.
- Codes: a cellphone number 082 123 4567 is not a quantity you add or subtract, it is an identifier.
Recognising that a code is not a calculable amount is part of number sense. You would never add two phone numbers together, but you would add two prices on a slip.
1.4 Comparing and ordering numbers
To make decisions we often compare numbers. The symbols \( < \) (less than), \( > \) (greater than) and \( = \) (equal to) let us state which is bigger. When ordering money or measurements, line up the place values and compare from the largest place value first.
Compare the rand part first: all are 38 or 39 rand. Boxer at R38,75 is the only 38, so it is cheapest. Between R39,90 and R39,95 the cents decide: 90 cents is less than 95 cents. So the order is Boxer R38,75 \( < \) Pick n Pay R39,90 \( < \) Spar R39,95. The cheapest is Boxer.
1.5 Negative numbers and the number line
A number line is a straight line with numbers placed in order, zero in the middle, positives to the right and negatives to the left. It helps us picture temperature, bank balances and altitude. Moving right means increasing; moving left means decreasing. If the temperature in Sutherland is -6 degrees at 06:00 and rises to 4 degrees by midday, it has increased by 10 degrees, because the distance from -6 to 4 on the number line is 10 steps.
1.6 Why this matters
Strong number sense is the foundation for everything that follows this year: rounding and estimating, working with ratios, calculating percentages, reading payslips, measuring, and interpreting maps and data. A learner who confidently reads R1 250,00, understands that -R150 means money owed, and can order prices to find the best deal is already thinking like a financially capable citizen. The rest of this guide simply extends these everyday number skills into more powerful tools.