Stimulating pre-service teachers’ content and pedagogical content knowledge on rational numbers

The transition from natural to rational numbers is difficult for most elementary school children. A major cause for these difficulties is assumed to be the “conceptual change” they need to undergo in order to see that several natural number properties do not apply to rational numbers. To appropriately handle pupils’ difficulties, teachers need well-developed content knowledge (CK) and pedagogical content knowledge (PCK). In the present study, a...