The idea, step by step
Numbers have positions
On this number line, numbers grow as you move right. Each equal step adds one. A number farther left is smaller.
Count spaces you move, not the tick you start on.
Order carefully
Find the smallest number first. Place the next smallest after it and keep checking the numbers that remain.
If two numbers have the same tens, compare the ones. For example, 63 comes before 67.
A common trap
Counting the starting tick as the first move.
Instead: Starting on 10 is no move yet. The first step right lands on 11.
See the thinking
Count the steps
Start at 10. Move three steps right. Where do you land?
- The first step lands on 11.
- The second lands on 12.
- The third lands on 13.
Order three numbers
Order 62, 56 and 60 from smallest to largest.
- 56 has fewer tens than 60 or 62.
- 60 comes before 62.
- Check that the numbers keep growing.
Check your understanding
Which is larger: 74 or 71?
Show answer
74
Both have seven tens. Four ones is more than one one.
Your turn
6 questions · Work at your own pace.
Read the questions online
- Which is smaller: 18 or 15?
- Order 34, 31 and 33 from smallest to largest.
- Start on 12. Move two steps right. Where do you land?
- Start on 15. Move three steps left. Where do you land?
- Order 105, 101 and 110 from smallest to largest.
- Noah says 68 is smaller than 65. Is he right? Explain.
Read the worked solutions
- Which is smaller: 18 or 15?
15 comes before 18.
15 - Order 34, 31 and 33 from smallest to largest.
All have three tens, so compare the ones.
31, 33, 34 - Start on 12. Move two steps right. Where do you land?
12 to 13 is one step; 13 to 14 is two.
14 - Start on 15. Move three steps left. Where do you land?
Count back: 14, 13, 12.
12 - Order 105, 101 and 110 from smallest to largest.
Count onwards from 101 to check.
101, 105, 110 - Noah says 68 is smaller than 65. Is he right? Explain.
Both have six tens; eight ones is more than five.
No. 68 is larger than 65.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Year 1 counting, place value and partitioning.
Official curriculum source ↗