The idea, step by step
Keep the jump the same
Counting in twos means adding two each time: 2, 4, 6, 8. Counting in fives gives 5, 10, 15, 20.
Say one number for each equal group. Count three groups of five as 5, 10, 15.
Start in a different place
You can count in twos from 3: 3, 5, 7, 9. The jump is still two.
For a missing number, check the jump before it and the jump after it. They must match the rule.
A common trap
Changing the jump partway through.
Instead: Choose the step size first. Add that same amount every time.
See the thinking
Count pairs
There are four pairs of socks. How many socks?
- Each pair has two socks.
- Count the pairs: 2, 4, 6, 8.
- There are eight socks.
A different start
Count in tens from 5. Write the next three numbers.
- Add ten to 5 to get 15.
- Add ten again to get 25.
- Add ten once more to get 35.
Check your understanding
What comes next: 15, 20, 25, __, counting in fives?
Show answer
30
Each jump adds five.
Your turn
6 questions · Work at your own pace.
Read the questions online
- Fill the gap: 2, 4, __, 8, 10.
- Write the next two numbers: 10, 20, 30, __, __.
- Fill the gaps: 5, __, 15, __, 25.
- There are three pairs of gloves. How many gloves?
- Count in twos from 3. Write the next three numbers.
- Six hands each have five fingers. Count in fives to find the fingers.
Read the worked solutions
- Fill the gap: 2, 4, __, 8, 10.
Add two each time.
6 - Write the next two numbers: 10, 20, 30, __, __.
Add ten for each new number.
40, 50 - Fill the gaps: 5, __, 15, __, 25.
Count in fives.
10, 20 - There are three pairs of gloves. How many gloves?
Count the pairs: 2, 4, 6.
6 gloves. - Count in twos from 3. Write the next three numbers.
Keep adding two.
5, 7, 9 - Six hands each have five fingers. Count in fives to find the fingers.
5, 10, 15, 20, 25, 30.
30 fingers.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Year 1 counting, place value and partitioning.
Official curriculum source ↗