Growth of pre-service teachers’ knowledge and teaching ideas about decimals and fractions : The case of Vivi

This paper discussed and analysed the growth of one pre-service teachers’ knowledge about decimals and fractions during a teaching experiment. Evidence of her progress is based on responses to written test and interview questions. This case shows with probing questions and appropriate teaching ideas, it is possible for a pre-service teacher with initially weak and fragmented knowledge about decimals and fractions to develop a meaningful knowledge about decimals and fractions. The stronger conceptual base provided by use of a concrete representation of decimals enabled Vivi to move away from reliance on memorised facts and rules and towards conceptually based explanations of ideas.