Negative numbers · Year 5
In Year 5 you learn: counting back through zero and negative numbers in temperatures.
Negative numbers are numbers below zero. We meet them in cold temperatures, bank overdrafts, floors below ground and depths below sea level. A number line is the best way to picture them: further left means smaller, so −8 is less than −2.
Key facts
- On a number line, numbers get smaller to the left: −7 < −3 < 0 < 2.
- Adding a positive moves right; subtracting a positive moves left.
- Multiplying or dividing: same signs give positive, different signs give negative.
- The difference between two temperatures is how far apart they are on the number line.
Worked examples
Example 1
It is −4 °C at dawn. By midday it is 7 °C warmer. What is the temperature at midday?
Answer: 3 °C
Example 2
−6 − (−9)
Answer: 3
Example 3
(−8) × 3 and (−24) ÷ (−6)
Answer: −24 and 4
Example 4
A diver is at −18 m. A seagull is 7 m above sea level. How far apart are they?
Answer: 25 m