We examined the type of errors on multiplication and division computation problems of 326 rising fifth graders enrolled in four elementary schools in Northern Portugal. We further examined whether there was a difference in the number of errors across age and whether there was an association between students' performance on number knowledge and…

To diagnose classroom situations is crucial for teachers' everyday practice. The approach of worked examples with errors seems promising to support the diagnosis of classroom situations in student teachers (Stark et al. in "Learn Instr" 21(1):22-33, 2011). To enhance that approach, error-explanation prompts and an adaptable feedback…