NUMBER

Number Lines

Learn the reliable method for number lines, then apply it to 11+ exam-style questions.

1 · WHAT YOU NEED TO KNOW

The idea

Equal intervals on a number line represent equal numerical changes.

Picture itMove along the number line
2 · THE METHOD

Follow these steps

  1. Find the difference between two labelled marks.
  2. Divide by the number of equal intervals.
  3. Count intervals—not marks—to locate the missing value.
3 · WORKED EXAMPLES

See the method in action

Example 1

Move one marked interval to the right. Which number belongs at the question mark?

12?each step is +3
  1. One interval adds 3: 12 + 3 = 15.
Answer: 15
Example 2

The first mark is 12 and the fifth is 24. What is the value of one interval?

1215?2124
  1. First identify the relevant place-value or representation relationship.
  2. Then the total change 12 is shared across 4 equal intervals: 12 ÷ 4 = 3.
  3. Finally, check the result against every value or position stated in the question.
Answer: 3
4 · ELEVENSPRINT TIP

A useful shortcut

Count intervals—not marks—to locate the missing value.

5 · COMMON MISTAKES

Watch out for these

6 · TRY IT YOURSELF

Three fresh questions

Ready to check the method? You will get three fresh, validated questions.