In this study, we examined the development of maths skills in 269 Estonian primary school children (119 boys and 150 girls; 20 classes). Testing was carried out over a three-year period (Grade 1-Grade 3). Before the last testing session, children's verbal skills and motivational orientations were also tested. In addition, teachers evaluated children's learning behaviour and provided information about their own teaching methods. The data were analysed using multilevel growth curve modelling. We found that children with higher levels of pre-maths skills developed at a faster rate. At the individual level, pre-maths skills and verbal ability were positively associated with maths achievement in Grade 3, and avoidance orientations (self-reported) and task-avoidant behaviour (teacher-reported) were negatively associated with maths achievement in Grade 3. At the classroom level, formalist teaching methods and teacher experience had a positive effect on students' maths performance. (Contains 3 tables, 1 figure and 1 note.)