Reception Maths: Before, after and between
Part of the Reception Maths numbers to 20 chapter. Chapter overview · whole chapter on one page
Before, after and between
Lee is on a bus. The stops are numbered. He wants to know which stop is next.
The number after is one more. The number before is one less. The number between two numbers sits in the middle of them, like 15 between 14 and 16.
Key ideas
- After: one more.
- Before: one less.
- Between: in the middle of two numbers.
- Smallest first: the number with fewest tens and ones.
Method. Find 14 on the number track. The number after it is the answer.
- Find 14. Put your finger on it.14
- Move one box to the right. Each box is one more or one less.14 + 1 = 15
- Write the answer. 15
Check. Check it: 15 − 1 = 14. ✓
Watch out. Move one box only. Do not write the number you started with.
Method. The number between 14 and 16 is in the middle of them.
- Find 14 and 16. Put your fingers on both numbers.14 ... 16
- Count on one from 14. The middle number is one more than the first.14 + 1 = 15
- Write the answer. 15
Check. Count on from 15 to 16: 15 + 1 = 16. ✓
Watch out. The number between is not one of the two you started with.
Method. Smallest first. Look at how many tens each number has, then the ones.
- Look at the tens of each number. More tens means a bigger number.17, 9, 12
- Put the smallest first. Then put the next smallest.9, 12, 17
- Write the numbers in order. Check you have not left one out.9, 12, 17
Check. There are 3 numbers in the question and 3 in the answer. ✓
Watch out. Compare the tens first. Only look at the ones if the tens are the same.
Watch out
Watch out: 9 is smaller than 10, even though 9 has only one digit. Smaller numbers come first.
Exam tip
Grown-up tip. Use the bus stops from a real trip, or a row of door numbers. Ask: “Which stop comes before this one?”
Exercise 2D Before, after and between
Non-calculatorMethod. Find 16 on the number track. The number after it is the answer.
- Find 16. Put your finger on it.16
- Move one box to the right. Each box is one more or one less.16 + 1 = 17
- Write the answer. 17
Check. Check it: 17 − 1 = 16. ✓
Watch out. Move one box only. Do not write the number you started with.
Method. Find 11 on the number track. The number before it is the answer.
- Find 11. Put your finger on it.11
- Move one box to the left. Each box is one more or one less.11 − 1 = 10
- Write the answer. 10
Check. Check it: 10 + 1 = 11. ✓
Watch out. Move one box only. Do not write the number you started with.
Method. The number between 8 and 10 is in the middle of them.
- Find 8 and 10. Put your fingers on both numbers.8 ... 10
- Count on one from 8. The middle number is one more than the first.8 + 1 = 9
- Write the answer. 9
Check. Count on from 9 to 10: 9 + 1 = 10. ✓
Watch out. The number between is not one of the two you started with.
Method. Find 9 on the number track. The number after it is the answer.
- Find 9. Put your finger on it.9
- Move one box to the right. Each box is one more or one less.9 + 1 = 10
- Write the answer. 10
Check. Check it: 10 − 1 = 9. ✓
Watch out. Move one box only. Do not write the number you started with.
Method. Find 20 on the number track. The number before it is the answer.
- Find 20. Put your finger on it.20
- Move one box to the left. Each box is one more or one less.20 − 1 = 19
- Write the answer. 19
Check. Check it: 19 + 1 = 20. ✓
Watch out. Move one box only. Do not write the number you started with.
Method. The number between 14 and 16 is in the middle of them.
- Find 14 and 16. Put your fingers on both numbers.14 ... 16
- Count on one from 14. The middle number is one more than the first.14 + 1 = 15
- Write the answer. 15
Check. Count on from 15 to 16: 15 + 1 = 16. ✓
Watch out. The number between is not one of the two you started with.
Method. Smallest first. Look at how many tens each number has, then the ones.
- Look at the tens of each number. More tens means a bigger number.14, 9, 17, 11
- Put the smallest first. Then put the next smallest.9, 11, 14, 17
- Write the numbers in order. Check you have not left one out.9, 11, 14, 17
Check. There are 4 numbers in the question and 4 in the answer. ✓
Watch out. Compare the tens first. Only look at the ones if the tens are the same.
Method. Smallest first. Look at how many tens each number has, then the ones.
- Look at the tens of each number. More tens means a bigger number.18, 12, 15
- Put the smallest first. Then put the next smallest.12, 15, 18
- Write the numbers in order. Check you have not left one out.12, 15, 18
Check. There are 3 numbers in the question and 3 in the answer. ✓
Watch out. Compare the tens first. Only look at the ones if the tens are the same.
Method. Count on from 13 to see which number comes later.
- Find 13 and 18. Put your finger on each number.13 and 18
- Count on from 13. The bigger number comes later when we count.14, 15, 16, 17, 18
- Write the answer. 18
Check. 18 comes after 13, so 18 is bigger. ✓
Watch out. The bigger number comes later when we count.
Method. The number between 12 and 14 is in the middle of them.
- Find 12 and 14. Put your fingers on both numbers.12 ... 14
- Count on one from 12. The middle number is one more than the first.12 + 1 = 13
- Write the answer. 13
Check. Count on from 13 to 14: 13 + 1 = 14. ✓
Watch out. The number between is not one of the two you started with.
Method. Look at the numbers. Find the next one in the pattern.
- Look at the numbers. Each number is one more than the one before.15, 16, 17
- Find the next number. One more than 17 is 18.17 + 1 = 18
- Write the answer. 18
Check. Count 15, 16, 17, 18. ✓
Watch out. Each number is one more than the one before it.
Method. Count up from 13 and look at which number comes next.
- Count from 13. Say the number after 13.13, 14
- Check the order. If we count up, 13 comes first and 14 comes after.13 before 14
- Write the answer. No. 13 comes before 14, so 14 comes after 13.
Check. Count 13, 14. Thirteen is first. ✓
Watch out. Count up to find which number comes first.