Step-by-step Maths Level 1: Number lines and number tracks
Part of the Step-by-step Maths Level 1 counting to 20 chapter. Chapter overview · whole chapter on one page
Number lines and number tracks
A number line shows the numbers in order, from left to right.
Each mark is one more than the mark before it. To count on, move right. To count back, move left.
Key ideas
- A number line goes up in ones from left to right.
- Count on means move right.
- Count back means move left.
Method. Start on 7 and count on three steps.
- Start on 7. This is where we begin.7
- Count on three jumps. Each jump moves one number to the right.8, 9, 10
- Write the answer. 10
Check. Count back three steps from 10: 9, 8, 7. You are back at 7.
Watch out. Count the jumps, not the numbers you land on.
Method. Look at the numbers next to the box.
- Look at the numbers either side. The box is between 11 and 13.11 and 13
- Count on one. After 11 comes 12.11 + 1 = 12
- Write the answer. 12
Check. 12 is one less than 13. It is correct.
Watch out. Read the number line from left to right.
Method. One step before means one less.
- Start at 15. We begin here.15
- Count back one step. The number to the left is one less.15 - 1 = 14
- Write the answer. 14
Check. Count on one from 14: 15. It works.
Watch out. Before means to the left, so the number gets smaller.
Watch out
Watch out. Count the jumps. If you start on 7 and count on 3, you land on 10, not 11.
Exam tip
Grown-up tip. Draw a number line on paper from 0 to 20. Move a counter along it. Ask your child to say where they land before they move.
Exercise 2D Number lines and counting on
Non-calculatorMethod. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.1 and 3 are next to the box
- Count on one. The number in the middle is one more than the one before.1 + 1 = 2
- Write the answer. 2
Check. Check: 2 is one less than 3. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.6 and 8 are next to the box
- Count on one. The number in the middle is one more than the one before.6 + 1 = 7
- Write the answer. 7
Check. Check: 7 is one less than 8. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Start on the number. Count on one jump at a time.
- Start on the number. We start here.8
- Count on 5 steps. Each step moves one number along.9, 10, 11, 12, 13
- Write the answer. 13
Check. Count back 5 steps from 13: you land on 8. ✓
Watch out. Count the jumps, not the numbers you land on.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.15 and 17 are next to the box
- Count on one. The number in the middle is one more than the one before.15 + 1 = 16
- Write the answer. 16
Check. Check: 16 is one less than 17. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.9 and 11 are next to the box
- Count on one. The number in the middle is one more than the one before.9 + 1 = 10
- Write the answer. 10
Check. Check: 10 is one less than 11. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Start on the number. Count on one jump at a time.
- Start on the number. We start here.4
- Count on 5 steps. Each step moves one number along.5, 6, 7, 8, 9
- Write the answer. 9
Check. Count back 5 steps from 9: you land on 4. ✓
Watch out. Count the jumps, not the numbers you land on.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.3 and 5 are next to the box
- Count on one. The number in the middle is one more than the one before.3 + 1 = 4
- Write the answer. 4
Check. Check: 4 is one less than 5. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.4 and 6 are next to the box
- Count on one. The number in the middle is one more than the one before.4 + 1 = 5
- Write the answer. 5
Check. Check: 5 is one less than 6. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Start on the number. Count on one jump at a time.
- Start on the number. We start here.6
- Count on 6 steps. Each step moves one number along.7, 8, 9, 10, 11, 12
- Write the answer. 12
Check. Count back 6 steps from 12: you land on 6. ✓
Watch out. Count the jumps, not the numbers you land on.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.9 and 11 are next to the box
- Count on one. The number in the middle is one more than the one before.9 + 1 = 10
- Write the answer. 10
Check. Check: 10 is one less than 11. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.14 and 16 are next to the box
- Count on one. The number in the middle is one more than the one before.14 + 1 = 15
- Write the answer. 15
Check. Check: 15 is one less than 16. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Start on the number. Count on one jump at a time.
- Start on the number. We start here.9
- Count on 5 steps. Each step moves one number along.10, 11, 12, 13, 14
- Write the answer. 14
Check. Count back 5 steps from 14: you land on 9. ✓
Watch out. Count the jumps, not the numbers you land on.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.1 and 3 are next to the box
- Count on one. The number in the middle is one more than the one before.1 + 1 = 2
- Write the answer. 2
Check. Check: 2 is one less than 3. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.0 and 2 are next to the box
- Count on one. The number in the middle is one more than the one before.0 + 1 = 1
- Write the answer. 1
Check. Check: 1 is one less than 2. ✓
Watch out. Read the number line from left to right. Each mark is one more.
Method. Start on the number. Count on one jump at a time.
- Start on the number. We start here.8
- Count on 6 steps. Each step moves one number along.9, 10, 11, 12, 13, 14
- Write the answer. 14
Check. Count back 6 steps from 14: you land on 8. ✓
Watch out. Count the jumps, not the numbers you land on.
Method. Look at the numbers next to the box. Count to find the missing number.
- Look at the numbers either side. The box is between two numbers.14 and 16 are next to the box
- Count on one. The number in the middle is one more than the one before.14 + 1 = 15
- Write the answer. 15
Check. Check: 15 is one less than 16. ✓
Watch out. Read the number line from left to right. Each mark is one more.