# Alan Cockerill▸ Task 6: Algorithms & Programming

Option 2: Design an activity that explores sequences of instructions.
Design an algorithm for doing a jigsaw puzzle.
Divide children into groups, and supply each group with a jigsaw puzzle. (The number of pieces and complexity of the puzzle can be adjusted to age and ability, but the children should be able to complete the puzzle, or at least make significant progress, in about 5 minutes. The children may be asked to complete the puzzle with or without the aid of a master picture.) Ask the children to discuss strategies for completing the puzzle, and then to work cooperatively to complete it. Each group may develop slightly different strategies, but that will only enrich the discussion that follows. After five minutes or so, ask the children to stop work, and ask each group to produce a written description of how they went about solving the puzzle. This might include steps like the following (though not necessarily in this order):
1. Turn all the pieces over, so the picture side is visible.
2. Sort the pieces into corners, side pieces, and other pieces.
3. Sort pieces according to their colour.
4. Sort pieces according to whether they are clearly part of some picture element, such as a person, animal or thing.
5. Assemble pieces into identifiable picture elements.
6. Join corners and side pieces to create a ‘frame’ for the picture.
7. Combine the various combinations identified to complete the puzzle, filling in any gaps as your go.
Ask each group to share their strategies, and then discuss what they have in common. Introduce the concepts of ‘decomposition’ (breaking the task down into smaller tasks that are less complex than the whole task), ‘abstraction’ (identifying key attributes such as ‘shape’, ‘colour’, ‘part of something I recognise’, and ‘algorithm’ (a procedure for solving a problem).
Collectively write an algorithm for completing a jigsaw, drawing on the best suggestions from each group.