Negative Numbers
Numbers below zero; they extend the number line to the left.
Key idea
Numbers below zero; they extend the number line to the left.
In depth
Negatives extend the number line left of zero and describe debts, temperatures below zero, or going backwards. The opposite of a is −a, and a number and its opposite sum to zero.
Worked example
A temperature of −5 °C is 5 degrees below freezing. Rising 8 degrees gives −5 + 8 = 3 °C.
Real-world uses
- Reading bank overdrafts, temperatures below zero and altitude below sea level
Common mistake
Thinking −5 is larger than −2. On the number line, −5 is further left, so it is smaller.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Negative Numbers?
Numbers below zero; they extend the number line to the left. It is a topic at the intermediate level in Arithmetic & Number Sense.
Where is Negative Numbers used in real life?
Real-world examples: Reading bank overdrafts, temperatures below zero and altitude below sea level.
What should I learn before Negative Numbers?
Make sure you are comfortable with Cube Numbers and Roots, the previous topic in Arithmetic & Number Sense.
What is a common mistake with Negative Numbers?
Thinking −5 is larger than −2. On the number line, −5 is further left, so it is smaller.
How can I practise Negative Numbers?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Negative Numbers?
Move on to Integers next.
Related intermediate topics in Arithmetic & Number Sense
- Long Multiplication – Multiply by each digit of the multiplier, shift by place value, then add partial products.
- Long Division – Divide, multiply, subtract and bring down repeatedly to get the quotient.
- Factors and Multiples – Factors divide a number exactly; multiples are its products with whole numbers.
- Divisibility Rules – Quick tests: by 2 last digit even, by 3 digit-sum divisible by 3, by 5 ends 0/5, by 9 digit-sum divisible by 9.
- Prime Numbers – A prime has exactly two positive divisors: 1 and itself.
- Composite Numbers – Numbers greater than 1 with more than two factors.