Four pictures (a,b,c,d) show distances and four pictures show (1,2,3,4) velocities.
The pictures are diagrams that show the movement of a cyclist in a street.
A person standing still in the street looks at the moving cyclist and draws the pictures. The distance is the distance of the cyclist to the person.

Phase 1 choose the pictures
Try to find combinations of pictures; try to find four pairs of pictures so that each picture of a distance combines with a picture of a velocity.

Phase 2 discussion on the forum
Write your result on the Forum: a? , b?, c?, d?

Compare your combination with the choices your partner made.
Two possibilities: agreement or disagreement!

When you agree you try together to design an explanation so you are able to explain to anybody else your choices.
When you do not agree you discuss and at the end of your discussion you have the same opinion and the same table!

Presentation: a story to tell

Write a short story to show other people by means of a real example (a cyclist, a walker in the street, a car) the kind of movement that relates with the table!
You can write two stories in relation with ax and bx and your partner writes the stories for c and d.
You read each others stories; you propose changes or you add some ideas.
At the end both of you are satisfied with the final result.