Step 1 Objective
Discuss work using mathematical language. Represent work using symbols and simple diagrams.
- 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 three lines so they do not cross.
- Draw three lines so they do cross.
- Show me where they cross.
- You have drawn some diagrams. Tell me how many lines there are and how many crossings (intersections) there are [you could put a large dot at each crossing]