Problem solving must be the focus of school mathematics in the 1980s…. Fundamental to the development of problem solving activity is an open mind, an attitude of curiosity and exploration… Mathematics teachers should create classroom environments in which problem solving can flourish… [it] is essentially a creative activity.
(National Council of Teachers of Mathematics, 1980,pages 2-4)
More recently, the National Council of Teachers of Mathematics (1989) has published 190