Stage: 2 Challenge Level: 
How many cubes will you start with?
Try making a shape and then counting the number of faces. Are there more than $28$ or fewer than $28$? Can you see how to change your shape to get exactly $28$ faces?
Working systematically. Visualising. Compound transformations. Representing. Tangram. Properties of numbers. Investigations. Interactivities. Addition & subtraction. Practical Activity.
Published November 2009,December 2009.
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