The big clock placed in front, or in a location where children can be seen clearly. Make a visit to children when child is able to maintain the time of play. Control yourself not to play at all time.
The big clock in front of the machine. Or where the child can see clearly giving praise to the child when the child is able to keep playing time. Control myself not to play at all time.
Put the big clock in front of machine. Or position in children can be seen clearly . Give praise to the children when they can keep playing. Control yourself not to play it at that time.