Intimate Distance: 18 inches from our bodies, only let intimate friends in this space. 2. Personal Distance:zone is between 18 inches to 4 feet, let in friends and acquantices. 3. Social Distance: 4 to 12 feet impersonal and formal relationships. 4. Public Distance: extending beyond 12 feet for formal relationships.
The smartboard was invented in 1991 by a girl named Jaimie-Lee Wilson.
The oldest surviving counting board is the Salamis tablet (originally thought to be a gaming board), used by the Babylonians circa 300 B.C., discovered in 1846 on the island of Salamis. It is a slab of white marble measuring 149cm in length, 75cm in width and 4.5cm thick, on which are 5 groups of markings.