Reception Maths: One more and one less

Key words. One more means the next number.

Method. One more is the next number. Add one to 4.

1. Start with 4. Count the things in the first group.
   4
2. Add one more. Count on one from the first number.
   4 + 1 = 5
3. Write the answer.
   5

Check. Count back one: 5 − 1 = 4. ✓

Watch out. One more is the next number, not the number after that.

Key words. One less means the number just before.

Method. One less is the number just before. Take one from 8.

1. Start with 8. Count the things in the group.
   8
2. Take one away. One less is one fewer.
   8 − 1 = 7
3. Write the answer.
   7

Check. Add one back: 7 + 1 = 8. ✓

Watch out. Take one away, and check that the number went down by one.

Key words. One more means the next number.

Method. One more is the next number. Add one to 9.

1. Start with 9. Count the things in the first group.
   9
2. Add one more. Count on one from the first number.
   9 + 1 = 10
3. Write the answer.
   10

Check. Count back one: 10 − 1 = 9. ✓

Watch out. One more is the next number, not the number after that.

Key words. One less means the number just before.

Method. One less is the number just before. Take one from 5.

1. Start with 5. Count the things in the group.
   5
2. Take one away. One less is one fewer.
   5 − 1 = 4
3. Write the answer.
   4

Check. Add one back: 4 + 1 = 5. ✓

Watch out. Take one away, and check that the number went down by one.

Key words. One more means the next number.

Method. One more is the next number. Add one to 14.

1. Start with 14. Count the things in the first group.
   14
2. Add one more. Count on one from the first number.
   14 + 1 = 15
3. Write the answer.
   15

Check. Count back one: 15 − 1 = 14. ✓

Watch out. One more is the next number, not the number after that.

Key words. One less means the number just before.

Method. One less is the number just before. Take one from 20.

1. Start with 20. Count the things in the group.
   20
2. Take one away. One less is one fewer.
   20 − 1 = 19
3. Write the answer.
   19

Check. Add one back: 19 + 1 = 20. ✓

Watch out. Take one away, and check that the number went down by one.

Method. Count the first group. Then add one more thing and count again.

1. Count the first group: 3. Touch each one once.
   3
2. Add one more. The new group has one more thing.
   3 + 1 = 4
3. Count the new group. Touch each one once to check.
   Now there are 4
4. Write the answer.
   4

Check. Count the new group again: 1 to 4. ✓

Watch out. Count the new thing too.

Method. Count the first group. Then add one more thing and count again.

1. Count the first group: 7. Touch each one once.
   7
2. Add one more. The new group has one more thing.
   7 + 1 = 8
3. Count the new group. Touch each one once to check.
   Now there are 8
4. Write the answer.
   8

Check. Count the new group again: 1 to 8. ✓

Watch out. Count the new thing too.

Key words. One less means the number just before.

Method. One less is the number just before. Take one from 7.

1. Start with 7. Count the things in the group.
   7
2. Take one away. One less is one fewer.
   7 − 1 = 6
3. Write the answer.
   6

Check. Add one back: 6 + 1 = 7. ✓

Watch out. Take one away, and check that the number went down by one.

Key words. One less means the number just before.

Method. One less is the number just before. Take one from 10.

1. Start with 10. Count the things in the group.
   10
2. Take one away. One less is one fewer.
   10 − 1 = 9
3. Write the answer.
   9

Check. Add one back: 9 + 1 = 10. ✓

Watch out. Take one away, and check that the number went down by one.

Key words. One more means the next number.

Method. One more is the next number. Add one to 12.

1. Start with 12. Count the things in the first group.
   12
2. Add one more. Count on one from the first number.
   12 + 1 = 13
3. Write the answer.
   13

Check. Count back one: 13 − 1 = 12. ✓

Watch out. One more is the next number, not the number after that.

Method. Count the balls in the first row. Then add one to get the next number.

1. Count the balls. Touch each one once.
   1, 2, 3, 4, 5, 6
2. Add one more ball. Count on one from 6.
   6 + 1 = 7
3. Write the answer.
   7

Check. Count back one from 7: 6. ✓

Watch out. One more than six is seven, not eight.

Method. Count on from 9 to see which number comes next.

1. Count from 9. Say the next number after 9.
   9, 10
2. Look at the step. Ten is the next number, so it is one more.
   9 + 1 = 10
3. Write the answer.
   Accept any answer that says 10 is the next number after 9, so it is one more.

Check. Count back one from 10: 9. ✓

Watch out. One more is always the next number.