Numbers to 20 · Usually met around P1
Counting on and counting back
On: 1 more each time. Back: 1 less each time.
How to do it
Method
On: 1 more each time. Back: 1 less each time
On: 12, 13, 14. Back: 15, 14, 13
Another way
Number line
Right a step: 1 more. Left a step: 1 less
In full
Counting on goes up one at a time, 1 more each time: 12, 13, 14, 15. Counting back goes down one at a time, 1 less each time: 15, 14, 13, 12. One more than a number is the number after it when you count on; one less is the number before it. Or look at a number line: one step right is 1 more, one step left is 1 less.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
Count back: 8, 7, □, 5
Show the answer and working
Answer: 6
Counting back, each is 1 less: after 7 comes 6.
Example 2
What number is 1 less than 1?
Show the answer and working
Answer: 0
1 less is the next number counting back: before 1 comes 0.
Example 3
Count back from 16 to 12: 16, □, □, □, 12
Fill in each box
Show the answer and working
Answer: 15，14，13
1 less each time: 16, 15, 14, 13, 12.
Practise it in the game →Numbers to 20 · Free to start, unlimited questions, no download