The most common type of classroom chair in an elementary classroom is one made from a durable, heavy-duty plastic that resists stains and scratches. Available in several colors to complement any decor, they have a contoured design to help students sit more comfortably. The legs can vary with wheels or glides and the base can be constructed with 4 legs, with a sled or cantilever base. Other types of classroom chairs, encourage more active sitting for students with an abundance of energy. While not your typical chair, they can be stools that wobble or an inflated ball with legs.