Enumeration skills in Down syndrome.
Kids with Down syndrome stall on lightning-fast naming of one-two-three items, so hit that subitizing skill first.
01Research in Context
What this study did
Margari et al. (2013) watched kids with Down syndrome look at dots on a screen.
They asked the kids to say how many dots popped up, from one to nine.
The team compared the Down syndrome group to kids of the same mental age and to kids of the same birth age.
What they found
The Down syndrome kids were slow and wrong on tiny sets of one, two, or three dots.
They did fine on bigger sets where you guess instead of count.
In short, they have a special glitch in subitizing — the fast see-and-say skill for very small numbers.
How this fits with other research
Lanfranchi et al. (2015) built on this by teaching the same kids a quick number game.
The game hit the 1-3 range hard and the kids’ math scores rose, proving the deficit can be trained.
Gomez et al. (2020) looked at kids with DCD and found the same subitizing dip.
Both studies show the glitch is not unique to Down syndrome, so check subitizing in any child who struggles with early math.
Boudreau et al. (2015) found that area and number comparison stay on par with mental age.
Pairing area tasks with dot drills gives you two ways in to the same number concept.
Why it matters
You now know the bottleneck is tiny-number speed, not overall number sense.
Start every early-math program with 1-3 subitizing cards, five minutes a day.
Track speed and accuracy; when those snap responses get fast, move to four and five.
Parents can run the drill at home using free dot-card apps while you keep data.
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02At a glance
03Original abstract
Individuals with Down syndrome (DS) exhibit various math difficulties which can be ascribed both to global intelligence level and/or to their atypical cognitive profile. In this light, it is crucial to investigate whether DS display deficits in basic numerical skills. In the present study, individuals with DS and two groups of typically developing (TD) children matched for mental and chronological age completed two delayed match-to-sample tasks in order to evaluate the functioning of visual enumeration skills. Children with DS showed a specific deficit in the discrimination of small numerosities (within the subitizing range) with respect to both mental and chronological age matched TD children. In contrast, the discrimination of larger numerosities, though lower than that of chronological age matched controls, was comparable to that of mental age matched controls. Finally, counting was less fluent but the understanding of cardinality seemed to be preserved in DS. These results suggest a deficit of the object tracking system underlying the parallel individuation of small numerosities and a typical - but developmentally delayed - acuity of the approximate number system for discrimination of larger numerosities.
Research in developmental disabilities, 2013 · doi:10.1016/j.ridd.2013.07.038