Final answer:
To ensure safety during a curl demo and roller placement, an open location with plenty of space should be chosen to minimize the risk of tripping or falling. By spreading out, the chances of accidents due to rolling balls can be reduced.
Step-by-step explanation:
When conducting a curl demo and roller placement, safety criteria should be considered to prevent tripping or falling. It is important to choose an open location with lots of space to spread out. This will reduce the chances of accidents due to rolling balls. By providing enough space, students will have ample room to move and perform the activity safely.