Children with ADHD scored lower on mathematics tests than a comparison group in a 2026 Italian study, but the findings did not show a clear, large weakness in their basic ability to estimate quantity.
This ability, often called number sense, involves judging roughly how many objects are present without counting. After researchers accounted for age, reasoning ability and math skill, the children with ADHD were as precise as the comparison group when estimating quantities.
What the study tested
The study compared 20 children with ADHD with 43 children with typical development. The children with ADHD were 7 to 17 years old; 14 had combined-type ADHD and six had mainly inattentive ADHD. None had taken ADHD medication.
The children estimated quantities in three formats: briefly shown black dots, sequential white flashes and their own finger taps recorded through key presses. They repeated the syllable “ba” during the tasks to discourage counting.
The ADHD group had a lower average math score, measured as a standardized z-score, than the comparison group: −0.50 versus +0.39. The ADHD group also scored lower on reasoning tests.
Similar accuracy, and adjusted precision
Accuracy did not differ between the groups. Average estimation error was about 1.2 items for both groups.
Before adjustment, the ADHD group was somewhat less precise overall. Its average Weber fraction was 0.188, compared with 0.16 in the comparison group. However, the statistical support for this difference was weak, and no individual task remained significant after correction for multiple comparisons.
Once age, reasoning and math skill were included in the analysis, the groups showed similar precision. The adjusted Weber fractions were 0.161 versus 0.157 for dot estimates, 0.167 versus 0.158 for flashes and 0.188 versus 0.191 for finger taps in the ADHD and comparison groups, respectively.
Older children tended to be more precise. Across all 63 children, those with higher math scores also made more precise and more accurate estimates, regardless of diagnosis.
What the findings do—and do not—show
The researchers said the results make a large number-sense deficit in ADHD unlikely, while noting that a small difference cannot be ruled out. The study does not establish why children with ADHD in this sample had lower math scores.
The researchers suggested that broader thinking skills, such as attention, working memory and self-monitoring, might play a role in the math gap. Those abilities were not measured in this study, so that explanation remains untested rather than a demonstrated cause.
Three children with ADHD also had dyscalculia. Removing them from the analysis did not change the results. A 2022 study by the same research group similarly found that 20 children with ADHD performed as well as 20 comparison children when selecting which of two dot groups contained more items, despite weaker performance in symbolic math.
Why the evidence remains limited
The study had a small ADHD group and used comparison data from an earlier study by the same team, although the tasks were identical. The flash sequences were faster for the children with ADHD. The sample was also unmedicated and too small for reliable comparisons by ADHD type or sex.
Because the analysis adjusted for math scores, it helps address whether quantity estimation differed beyond overall math performance, but it also makes the relationship between number sense and math achievement difficult to interpret as a cause-and-effect pathway. Larger studies that directly measure attention and working memory are needed to identify what may contribute to math difficulties in ADHD.
AI tools were used to assist with the preparation of this article under our editorial standards.
Leave a Reply