Age 11 to 14 Challenge Level:
It is certainly worthwhile looking at gradually increasing the size
of the squares. With younger pupils it would be good to allow them
to discuss the situation for even sided squares and those with a
side that is a multiple of 3. For older/more able pupils its a good
idea to go at least as far as a 43 by 43 square! When a large
number have been tried I would suggest that pupils try to examine
their "system" for getting the least number of squares.