Step 2 Objective

Begin to organise work. Use and interpret mathematical symbols and diagrams.


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.

  • For each diagram explain how many lines and how many crossings there are. Write this down next to each diagram.
  • What is the best way of writing this information down?