[@Azereiah][@liferusher]

Having suddenly been hit by an idea, Avarius quickly sits up and excitedly rummages through Brunhilde's supply bag. 
He finds the deflated beach ball and marker pens he was looking for.
As the girls continue to play and exercise (more the former than the later) he goes about inflating the ball and writing all over it. 
Sixty mathematic problems to be exact. 
Each one resembling one minute of break time. Unsure of his students current academic level Avarius broke the questions into ten groups of six.
Each group would have two easy, two intermediate, one challenging and one trick question. Every correct answer gave the girls one minute of free leisure time.

There were however a few rules;
the girls would each given a marker pen, they had to take turns answering a question. 
They had to stay in their own designated area a short distant apart from each other. 
Lastly their eyes must be shut unless they are holding the beach ball, this meant they had to catch it with their eyes closed. A dropped ball could be difficult to find.

The teacher would have it ready by the time they had finished their other activities and this one would lead into a lunch break. When they are ready he explains the premises of the exercise  

The ball was large and soft, and the rubber squeaked in their hands. At this distance, with expectation alone, this exercise could be played by non-elementals yet it was still good for honing the senses.