Task 2
Trains
Join rods end to end, name the structure and begin to record it symbolically.
We do
A train is made by placing more than one rod end to end.
- Build red and light green.
- Build two reds.
Name each train using colour names, then record it with colour letters. Listen for different sensible ways pupils describe repeated rods.
Teacher note: This begins to set the stage for compact expressions such as 3g for three light-green rods.
Your turn — Build and record
Build each train on your Show Me board, then record it using colour letters.
- three light greens
- pink, red, pink
- two yellows and a white
- red, two light greens and a pink
Can you write any of the trains in more than one sensible way?
Feedback / teacher prompts
- How did you choose to record repeated rods?
- Which representations are easiest to read?
Your turn — Make your own
- Make a train of two different rods and name it.
- Make a train of two rods of the same colour and name it.
- Make a train of three different rods and name it.
- Make a three-rod train in which two rods are the same colour.
What could you change?
- Use more rods.
- Restrict the number of colours.
- Give the notation and ask pupils to build it.
- Show a train and hide one rod.
- Ask pupils to create a train for a partner to record.
Rehearse the teaching
For a task worth practising, work in pairs. One person teaches while the other responds as a pupil using the rods. Model enough to get the pupil started, then stop explaining and question their thinking. Swap roles.
Reflect: What was harder to explain than you expected? Which wording or question worked well?