One of the keys to the rich nature of the activities is that the cards are chosen so that common misconceptions are included.  These will be matches for other cells on the grid, but the misconceptions may arise through the dialogue surrounding the piece of work.  This should be drawn out by the teacher and used to further learning.  As an example consider the following activity:

Two types of misconception in particular are included here.  Firstly, if a student believes that you find area by adding up the side lengths they might want to place the ‘24cm²’ card on the top left cell.  Likewise this confusion between area and perimeter might result in ‘60cm²’ being placed on the middle right cell. Also, if a pupil is not clear about the appropriate unit, the fact that ‘16cm’ and ‘16cm²’ are both included provides opportunity to address this.

Another feature of Stick on the Maths that contributes to its rich nature is the fact that many of the cards can be placed in more than one position on the grid.  As a result, it might be possible for many of the cards to be placed correctly, only to find that the last one or two cannot be placed.  This is likely to result in cognitive conflict and therefore some interesting reasoning. Take a look at this example: