In making squares, you should be tactful in letting which group of children do the easy and difficult tasks.
For the structured learners, you should set aside an easy task for them. Get them to make squares.
Whereas the advanced learner, give them the difficult one; complete the task into a square.
Though they do not look simple but with practice, they will surely get the tasks right.
Try using the same size squares in all possible ways to see the possibility that you can make it in different ways.
It'll be fun!