ABSTRACT

It is remarkable how seldom adults use the 'proper' way to work out a calculation. Even adults who do know the standard working methods in mathematics often use their own, quite idiosyncratic ways of working out an answer to an everyday life skills math problem. Adults quite often use very concrete ways of calculating, for example using fingers to work out how many days until a special date, and may use quite different working methods for the same problem at different times. Most often adults \vill rely on approximation rather than exact computation.