Professional competence of mathematics teachers in dealing with tasks in lesson planning

Teachers' professional competence to select tasks and prepare the task implementation is considered important for instruction that initiates meaningful learning. Teachers' professional knowledge and individual planning processes are discussed as reasons for individual differences in the quality of planning products, such as the selected tasks and preparation of task implementation. In a cross-sectional study, future and active secondary teachers' professional knowledge, their task-related lesson planning processes and planning products for fraction learning were assessed. Professional knowledge is related to the quality of teachers’ planning process, and this quality can be explained by noticing and reasoning during the task analysis process.