Subitizing and counting impairments in children with developmental coordination disorder.
Kids with DCD are slow and error-prone at both "seeing" and counting small sets, a likely root of their later math struggles.
01Research in Context
What this study did
Gomez et al. (2020) tested how fast and how well kids with developmental coordination disorder (DCD) can see and count small sets of dots.
They used two quick tasks: rapid subitizing (naming "how many" in a flash) and untimed counting. Kids with DCD were matched to same-age peers without motor delays.
What they found
Children with DCD were both slower and less accurate on every dot task. The gap showed up for tiny sets you should just "see" (1-3 dots) and for larger sets you have to count.
The authors say these early hiccups in "seeing" and "counting" may help explain why math homework later feels so hard for these kids.
How this fits with other research
Pieters et al. (2012) saw the same group of kids lag 1-2 years behind in math facts and calculation. Alice's team pins part of that delay on the very first step: getting the right number of items onto the page.
Harrowell et al. (2018) followed the story into high school. Teens with DCD earned a median of only 2 GCSEs versus 7 for peers, showing the school gap keeps widening when early number woes go unnoticed.
Ceulemans et al. (2014) looked at adolescents with math learning disorder (MLD) and found normal subitizing speed and accuracy. The clash looks odd, but the kids differ: DCD plus motor planning issues versus MLD alone. Method and diagnosis, not a true contradiction.
Why it matters
If you assess or teach a child with DCD, build in quick dot-pattern drills (1-3 items) and watch counting fluency. Catching the slowness early gives you a concrete baseline for IEP goals and tells you where to add visual supports or extra time before math concepts pile up.
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02At a glance
03Original abstract
Developmental coordination disorder (DCD) interferes with academic achievement and daily life, and is associated with persistent academic difficulties, in particular within mathematical learning. In the present study, we aimed to study numerical cognition using an approach that taps very basic numerical processes such as subitizing and counting abilities in DCD. We used a counting task and a subitizing task in forty 7-10 years-old children with or without DCD. In both tasks, children were presented with arrays of one to eight dots and asked to name aloud the number of dots as accurately and quickly as possible. In the subitizing task, dots were presented during 250 ms whereas in the counting task they stayed on the screen until the participants gave a verbal response. The results showed that children with DCD were less accurate and slower in the two enumeration tasks (with and without a time limit), providing evidence that DCD impairs both counting and subitizing. These impairments might have a deleterious impact on the ability to improve the acuity of the Approximate Number System through counting, and thus could play a role in the underachievement of children with DCD in mathematics.
Research in developmental disabilities, 2020 · doi:10.1016/j.ridd.2020.103717