Step 8 Objective

Solve substantial problems by breaking them into simpler tasks, using a range of efficient techniques, methods and resources, including ICT.


What if pupils find this a barrier?

diagram showing three lines crossing

Line Crossings

  • Draw three straight lines (line segments) so that some cross over each other.
  • How many crossings are there?
  • Try different arrangements of the lines. What is the maximum number of possible crossings?
  • Try using more lines.
  • Is there a rule for the maximum for any number of lines? If so, write it down.

Use the problem Line Crossings.

How did you draw your line patterns to make sure that you had the maximum number of crossings?

Look at the table of results:

  • Is there a good pattern or not?
  • How would the result table help to show if you had made any mistakes?
  • How would you check if your predictions are correct?