3
Spot the swap
Learner’s Book 1: Unit 1, p. 20
GoalNotice when two numbers are in the wrong places on a number track, say which numbers were swapped, and write the numbers 1 to 10.
New words
swapped · two things that changed placescorrect · right, with no mistakewrite · make the number with a pencil
Explanation
On a correct number track every number is in its own place. Sometimes two numbers swap places and the track is wrong. Say the numbers in order and listen for a mistake: 1, 2, 7 … that is not right! After 2 comes 3. Find the two numbers in the wrong places and swap them back. Writing the numbers carefully helps you to remember them: write 1, 2, 3 up to 10.
Top: the correct track. Bottom: 3 and 7 have swapped.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 1 | 2 | 7 | 4 | 5 | 6 | 3 | 8 | 9 | 10 |
Worked examples
| 1 | 2 | 3 | 6 | 5 | 4 | 7 | 8 | 9 | 10 |
To write 1, start at the top and draw one straight line down. To write 7, draw a line across the top and then a slanting line down.
| 1 | 0 |
Class activity
Swap detective: a grown-up lays cards 1 to 10 in order, closes your eyes and swaps two cards. Open your eyes and say which two numbers are in the wrong places. Swap them back. Then write all the numbers 1 to 10 in a row.
Practice
1
Which two numbers are swapped?
| 1 | 2 | 3 | 4 | 5 | 9 | 7 | 8 | 6 | 10 |
6 and 9
2
Which two numbers are swapped?
| 1 | 5 | 3 | 4 | 2 | 6 | 7 | 8 | 9 | 10 |
2 and 5
3
Write the numbers from 1 to 10 in order.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
4
Is this track correct? 1, 2, 3, 4, 5, 6, 8, 7, 9, 10
No. 7 and 8 have swapped places.