Back through zero in ones
Keep subtracting 1 each time.
The count does not stop at zero.
Year 4
Count backwards through zero to include negative numbers
Count backwards across zero and use the pattern to keep going into negative numbers.
Lesson overview
Number - number and place value
When we count backwards, we subtract the same amount each time. Zero is not the end of the pattern. If we keep subtracting, we move into negative numbers.
Back in steps of 100
Subtract 100 each time.
Each step is one hundred less.
Negative numbers stay in order
Numbers further left are smaller.
-3 is less than -2 because it is further left on the number line.
Worked example
Continue the sequence 150, 50, -50, ...
- Look for the change between the numbers.
- Each step subtracts 100.
- Subtract 100 from -50.
- The next number is -150.
Round 1: Learn it
Track the step carefully and notice when the count crosses zero.
Finish this round to unlock Round 2: Show you know it.
Question 1
Count back in 1s: 2, 1, 0, __
Question 2
Which number comes after 0 when counting back?
Question 3
Count back in 100s: 300, 200, 100, 0, __
Question 4
Which sequence is counting backwards correctly?
Question 5
Which number is smaller?
Common mistakes
Watch for these as you work through the lesson.
- Stopping at zero instead of continuing the pattern.
- Adding instead of subtracting when counting backwards.
- Forgetting that negative numbers get smaller as they move left.
Related topics
These ideas connect closely to this lesson.
- Count in multiples of 6, 7, 9, 25 and 1000.
- Order and compare numbers beyond 1000.