According to the British Dyslexia Association, Dyscalculia is a specific and persistent difficulty in understanding numbers which can lead to a diverse range of difficulties with mathematics (Association, 2022). As Dr. Butterworth suggests dyscalculia has no set definition internationally and its definition depends on politics (Made for Math, 2023). It is not very well researched.
He claims that dyscalculia can manifest itself with various comorbidities and that is one factor why it has not been researched well. It can be present in people with good working memory and in professional software engineers (Butterworth, Varma and Laurillard, 2011) as well as in people with developmental disorders. Professor Butterworth claims that our ability to count is genetic and even other species can count as well. For example, lions will attack intruders only if they outnumber them (Made for Math, 2023). According to his research the greatest predictor of dyscalculia is , therefore, the ability to enumerate a set of objects and compare the numerosities in arrays of dots (Butterworth, Varma and Laurillard, 2011).
We usually refer to these as ‘number sense’ and it is akin to phonological awareness in dyslexia. Humans use 3 predominant mechanisms to discriminate number quantity, or numerosity (Butterworth, Gallistel and Vallortigara, 2018). These are: subitizing, or knowing the amount without counting, for a group of 1-4 objects, serial enumeration for a group of 5-9 objects and large numbers for all other groups. According to studies (Butterworth, 2005), children with developmental dyscalculia cannot subitize but enumerate even the small sets which proves that the ability to subitize is the cornerstone of number sense.
Another foundation for number sense is the ability to compare symbolic and non-symbolic magnitude. Butterworth (Made for Math, 2023) uses three ways to assess number sense: symbolic to symbolic, non-symbolic to non-symbolic and symbolic to non-symbolic magnitude comparison. In symbolic magnitude comparison learners compare numerals to numerals while in non-symbolic tests they compare dot patterns. Ansari (Price and Ansari, 2013) cites studies where symbol comparison only was used. He, like many other, referenced in his work, researchers claim that symbolic magnitude comparison is a predictor of maths skills and primary developmental dyscalculia, while secondary dyscalculia has other origins.
Butterworth (Butterworth, Gallistel and Vallortigara, 2018) asserts, however, the inability to map number symbols (symbolic) to number magnitudes (non-symbolic)is at the core of dyscalculia. [1] Another strong predictor of maths ability is finger agnosia, or inability to correlate the finger counting and quantity[2] . The studies conducted with brain imaging suggest that individuals with dyscalculia have thinner grey matter in the regions, such as intraparietal sulci (IPS), than those who don’t have maths difficulties.
Apart from that maths learning is predominantly based on development of visual and spatial cognition and working memory. The latter helps with quick fact recall and according to other researchers (Price and Ansari, 2013) there is a “tight coupling” between deficits in working memory and maths. Very often this type of dyscalculia is categorised as primary while secondary dyscalculia is described as based on arithmetic deficits. [3] (Price and Ansari, 2013)
