Temperature below zero
A temperature of -3 degrees is colder than -1 degree.
Further left means a smaller number.
Year 5
Interpret negative numbers in context and count forwards and backwards with positive and negative whole numbers, including through zero
Use number lines and real contexts to understand negative numbers and move through zero accurately.
Lesson overview
Number - number and place value
Negative numbers are less than zero. They are useful in real situations such as temperatures, lifts and money. When we move right on a number line, numbers increase. When we move left, numbers decrease.
Count through zero
-2, -1, 0, 1, 2 does not stop at zero.
Zero is in the middle of positive and negative whole numbers.
Use a real context
Floor -1 is one level below floor 0.
below ground
ground level
above ground
Negative numbers often describe a position below a starting point.
Worked example
A lift moves from floor 2 down 5 floors. Which floor does it reach?
- Start at floor 2.
- Move back one floor at a time.
- Pass through 0 and keep counting backwards.
- The lift reaches floor -3.
Round 1: Learn it
Use the direction of movement and the order on the number line carefully.
Finish this round to unlock Round 2: Show you know it.
Question 1
Which temperature is colder?
Question 2
Count on: -3, -2, -1, 0, __
Question 3
A diver is at -4 m and rises to -1 m. Has the depth increased or decreased?
Question 4
Count back: 2, 1, 0, -1, __
Question 5
Which floor is one level below floor 0?
Common mistakes
Watch for these as you work through the lesson.
- Thinking -1 is smaller than -3 because 1 is smaller than 3.
- Stopping at zero instead of continuing the count.
- Mixing up forwards and backwards movement on the number line.
Related topics
These ideas connect closely to this lesson.
- Count forwards or backwards in steps of powers of 10 for any given number up to 1,000,000.
- Round any number up to 1,000,000 to the nearest 10, 100, 1000, 10,000 and 100,000.