Kirsti KislenkoA study about students’ beliefs and attitudes towards mathematics was carried out in Estonia in early 2006. The study aimed, firstly, to investigate students’ views towards mathematics and the underlying rationale, and secondly, to gain an understanding of the regular mathematics classroom activities in Estonia. The study used methodological triangulation, that is to use different methods on the same object of the study (Cohen, Manion, & Morrison, 2000). Firstly, a web-based Likert-scale questionnaire with 98 statements about beliefs in mathematics was administered to seven schools in an urban area in Estonia. Five hundred and eighty students from grades 7 (14 yrs.), 9 (16 yrs.), and 11 (18 yrs.) completed the questionnaire. Secondly, 26 semi-structured interviews were conducted with students and teachers for illuminating their thoughts about mathematics, and the learning and teaching of mathematics. Thirdly, during a three month period I participated in 11 teachers? lessons observing 55 mathematics lessons. Field notes gathered reflected a general picture of the classroom activities, teachers’ activities, methods, behaviour, relationship with students, and so on; and also personal impressions from different situations that I found interesting. Participants of the round table will be asked to consider the following questions: What are the appropriate tools for these kinds of investigations? What are the strengths and weaknesses of the methods used in my study? What are the possible strengths and weaknesses in combining quantitative and qualitative data collection methods?