Blackboard (chalkboard): description, materials, history and uses Blackboard A blackboard (chalkboard) is a reusable writing surface used for teaching, display, and signage. This article covers its construction, history, common uses, variations, and modern…
Overhead projector: design, history, and educational uses Overhead projector Overview of the overhead projector (OHP): how it works, key parts, historical development, classroom and meeting uses, and reasons it was largely superseded by digital devices.
