Number & place value
Counting to 100
Year 1 · Year 2
- ✓Count forwards to 100, starting from any number.
- ✓Count backwards from 100, starting from any number.
- ✓Count in steps of 2s, 5s and 10s.
- ✓Find one more or one less than a given number.
Key concepts
When you count forwards, you say numbers in order from smallest to biggest. Each number is one more than the number before it. For example, 1, 2, 3, 4, 5...
When you count backwards, you say numbers in order from biggest to smallest. Each number is one less than the number before it. For example, 10, 9, 8, 7, 6...
Counting in 2s means you say every second number. You are adding 2 each time. This is useful for counting pairs of things. For example, 2, 4, 6, 8, 10...
Counting in 5s means you say every fifth number. You are adding 5 each time. The numbers you say will always end in a 0 or a 5. For example, 5, 10, 15, 20, 25...
Counting in 10s means you say every tenth number. You are adding 10 each time. The numbers you say will always end in a 0. For example, 10, 20, 30, 40, 50...
'One more' than a number is the next number when you count forwards. It means adding 1 to the number. For example, one more than 7 is 8.
'One less' than a number is the number before it when you count forwards. It means taking away 1 from the number. For example, one less than 7 is 6.
Key facts to remember
- 1When you count forwards, numbers get bigger.
- 2When you count backwards, numbers get smaller.
- 3Counting in 2s means you are adding 2 each time.
- 4When you count in 5s, the numbers always end in a 0 or a 5.
- 5When you count in 10s, the numbers always end in a 0.
- 6'One more' means the number that comes just after.
- 7'One less' means the number that comes just before.
Worked examples
Example 1
Count forwards from 35 to 42.
Answer
35, 36, 37, 38, 39, 40, 41, 42
Example 2
Count backwards from 20 to 14.
Answer
20, 19, 18, 17, 16, 15, 14
Example 3
Complete the sequence by counting in 10s: 10, 20, ___, 40, ___, 60.
Answer
10, 20, 30, 40, 50, 60
This is counting in 10s, so each number ends in a 0.
Example 4
What is one more than 59? What is one less than 59?
Answer
One more than 59 is 60. One less than 59 is 58.
Common mistakes
- ✗Missing numbers when counting forwards or backwards, especially when crossing a 'tens' boundary (e.g., 29, 30, 31).
- ✗Confusing 'one more' with 'one less'.
- ✗Not recognising the patterns when counting in 2s, 5s, or 10s (e.g., thinking 5, 10, 16 instead of 15).
- ✗Starting from 0 when asked to count from a different number.
Exam tips
- ★Use a number line or a 100 square to help you count.
- ★Practise counting out loud regularly, both forwards and backwards.
- ★Look for patterns in numbers, especially when counting in 2s, 5s, or 10s.
- ★Always check if the question asks for 'one more' or 'one less'.
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