Step-by-step Maths Level 2: Finding the difference by counting up
Part of the Step-by-step Maths Level 2 taking away within 20 chapter. Chapter overview · whole chapter on one page
Finding the difference by counting up
The difference is how far apart two numbers are.
Count up from the smaller number to the bigger one. The number of steps is the difference.
Key ideas
- Difference means how far apart.
- Count up from the smaller number.
- The number of steps is the answer.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 12. We count up to the bigger number.12
- Count up to 17. Count each step as you go.17 - 12 = 5
- Write the difference. The number of steps is the difference.5
Check. 12 + 5 = 17. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 6. We count up to the bigger number.6
- Count up to 14. Count each step as you go.14 - 6 = 8
- Write the difference. The number of steps is the difference.8
Check. 6 + 8 = 14. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 9. We count up to the bigger number.9
- Count up to 15. Count each step as you go.15 - 9 = 6
- Write the difference. The number of steps is the difference.6
Check. 9 + 6 = 15. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Watch out
Watch out. Count the steps, not the numbers. From 12 to 17 there are 5 steps, not 6.
Exam tip
Grown-up tip. Ask: “How many more is 17 than 12?” Count up on fingers.
Exercise 6B Practice: finding the difference
Non-calculatorMethod. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 1. We count up to the bigger number.1
- Count up to 13. Count each step as you go.13 - 1 = 12
- Write the difference. The number of steps is the difference.12
Check. 1 + 12 = 13. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 3. We count up to the bigger number.3
- Count up to 16. Count each step as you go.16 - 3 = 13
- Write the difference. The number of steps is the difference.13
Check. 3 + 13 = 16. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 1. We count up to the bigger number.1
- Count up to 3. Count each step as you go.3 - 1 = 2
- Write the difference. The number of steps is the difference.2
Check. 1 + 2 = 3. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 6. We count up to the bigger number.6
- Count up to 10. Count each step as you go.10 - 6 = 4
- Write the difference. The number of steps is the difference.4
Check. 6 + 4 = 10. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 11. We count up to the bigger number.11
- Count up to 16. Count each step as you go.16 - 11 = 5
- Write the difference. The number of steps is the difference.5
Check. 11 + 5 = 16. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 2. We count up to the bigger number.2
- Count up to 16. Count each step as you go.16 - 2 = 14
- Write the difference. The number of steps is the difference.14
Check. 2 + 14 = 16. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 4. We count up to the bigger number.4
- Count up to 16. Count each step as you go.16 - 4 = 12
- Write the difference. The number of steps is the difference.12
Check. 4 + 12 = 16. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 2. We count up to the bigger number.2
- Count up to 14. Count each step as you go.14 - 2 = 12
- Write the difference. The number of steps is the difference.12
Check. 2 + 12 = 14. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 15. We count up to the bigger number.15
- Count up to 20. Count each step as you go.20 - 15 = 5
- Write the difference. The number of steps is the difference.5
Check. 15 + 5 = 20. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 1. We count up to the bigger number.1
- Count up to 8. Count each step as you go.8 - 1 = 7
- Write the difference. The number of steps is the difference.7
Check. 1 + 7 = 8. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 12. We count up to the bigger number.12
- Count up to 14. Count each step as you go.14 - 12 = 2
- Write the difference. The number of steps is the difference.2
Check. 12 + 2 = 14. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 2. We count up to the bigger number.2
- Count up to 17. Count each step as you go.17 - 2 = 15
- Write the difference. The number of steps is the difference.15
Check. 2 + 15 = 17. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 7. We count up to the bigger number.7
- Count up to 16. Count each step as you go.16 - 7 = 9
- Write the difference. The number of steps is the difference.9
Check. 7 + 9 = 16. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 1. We count up to the bigger number.1
- Count up to 9. Count each step as you go.9 - 1 = 8
- Write the difference. The number of steps is the difference.8
Check. 1 + 8 = 9. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 1. We count up to the bigger number.1
- Count up to 5. Count each step as you go.5 - 1 = 4
- Write the difference. The number of steps is the difference.4
Check. 1 + 4 = 5. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.
Method. The difference is how far apart the numbers are. Count up from the smaller number.
- Start at the smaller number, 2. We count up to the bigger number.2
- Count up to 12. Count each step as you go.12 - 2 = 10
- Write the difference. The number of steps is the difference.10
Check. 2 + 10 = 12. The difference is right.
Watch out. The difference is not the bigger number. It is the number of steps between them.