摘要:The purpose of this study was to meta-analyze the effectivity of interventions for children with mathematical difficulties. Furthermore, we investigated whether the fit between characteristics of participants and interventions was a decisive factor. Thirty-five evaluation studies that used pre-post-control group designs with at least 10 participants per group were analyzed. Using a random-effects model, we found a high, significant mean effect ( = 0.83) for the standardized mean difference. Moreover, a significant effect was found for studies that used direct or assisted instruction, that fostered basic arithmetical competencies, and that used single-subject settings. Effect size was not moderated by administration mode (computer-based vs. face-to-face intervention) or by whether interventions were derived from theory. Interventions for children with at-risk dyscalculia were effective on average. Results of the fit between characteristics of the participants and intervention characteristics are provided. In summary, mathematics interventions are found to be effective for children with mathematical difficulties, though there was a high effect size variance between studies. Keywords:  math difficulties , arithmetical competencies , children , intervention characteristics , intervention effects