ABSTRACT
The word 'algebra' comes from a ninth-century book by Al-Khwarizmi called Hisab al-jabr w'al-muqabala. It was a blend of many mathematical traditions including Babylonian, Indian and Greek, and included the solution of problems of inheritance and property division. In algebra, if it is a number it is represented by a letter such as 'a' or 'x'. Algebra is a very powerful way of expressing patterns concisely. It is concerned with generalities and finding equivalences among expressions. The practice in mental arithmetic is useful, as well as the discussion that might occur if more than one rule were suggested. One of the perennial complaints about children's mathematics is that they can carry out calculations with numbers but are unable to apply these to appropriate practical situations. Some investigations, especially with calculators, challenge the children to solve equations by trial and improvement.
