They first drew a picture in a small area, without being told what they would be doing with it. They then were given a large piece of squared paper and had to decide on their own scale factors to enlarge their drawings by….those with particularly intricate drawings quickly realised they had a tougher job!
Finally, they thought about how the area would increase with their enlargements and worked out the scale factor linked to the area scale factor. They realised that if there original picture had an area of 12squares and they enlarged with a scale factor of 3, then their scaled drawing had an enlargement of 108squares, or 12×9…or 12×32