Instructional design research promotes interactive and adaptive scaffolds as features of educational technology. Mathematics education research can guide elaborated fractions curricula to develop basic fraction concepts while challenging the natural number bias. Thus, we developed theory-grounded interactive material for learning fractions providing scaffolds in an eBook. Evaluating both, curriculum and scaffolds, we split 745 high-achieving and 260 low-achieving 6th graders into three groups: Scaffolded Curriculum group (using the eBook on iPads), Curriculum group (using a paper copy of our developed material), and Traditional group (using conventional textbooks). Generalized linear mixed models revealed diverse positive effects on the achievement of students in the experimental conditions: Results showed that high-achieving students did benefit from the curriculum, regardless of whether it was presented with or without scaffolds, while for low-achieving students using scaffolds was decisive. This suggests that interactive and adaptive scaffolds can support students in learning mathematical concepts, especially for low-achieving students.