The discussion of pupils with the teacher as well as discussions among pupils are important elements of constructivist-led education. Discussions are organized in such a way that pupils discover something new, formulate a hypothesis, discuss different solutions of the assigned task, etc.
To give pupils enough space for this is often very difficult for teachers because they cannot prepare such communication in advance and have to react quickly to the situation which emerges in the classroom. In a lesson, the teacher asks a number of questions, most of which are not prepared in advance.
The questions we are interested in are related to mathematics. We work with the concept of "good" questions developed originally by Sullivan and Clarke.
The main characteristics of "good" questions include the following: a) there exist several answers that can be accepted; b) more than mere reference to known facts is required; c) discussion is provoked; c) includes motivational function in lifelong education; d) pupils may learn something when they answer it and/or discuss it; and, e) teachers can learn something about their pupils from the pupils' answers. The contribution focused mainly on the following issues: What does a "good" question consist of? How to create "good" questions? How to use "good" questions in the classroom?