Step 3 Objective
Begin to refine ways of recording and use appropriate mathematical symbols correctly.
- Examples of what pupils should
know and be able to do - Probing questions
- What if pupils find
this a barrier?
What if pupils find this a barrier?
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.
- Draw other diagrams using only four (or five) lines; how many different numbers of intersections (crossings) can you get?
- How many more diagrams with a different number of intersections can you draw using four (or five) lines?
- How might you record the maximum number of crossings for three, four, five lines?
- Are there other ways?