Poor Reading: A Deep Dive
The link between dyscalculia and dysgraphia
How the causes of dyscalculia relate to dysgraphia
Dyscalculia has neurological and cognitive origins. Interestingly, some of the same underlying neurological factors in dyscalculia can also lead to dysgraphia, a learning disorder affecting writing skills. It’s not uncommon for the two to co-occur, and the overlap in symptoms often points to shared root causes:
Visuo-spatial processing deficits
A child with dyscalculia might struggle with spatial representation of numbers (for example, placing numbers on a number line or aligning columns). This spatial confusion can carry over into handwriting. Research in dysgraphia shows that a subtype called spatial dysgraphia is “usually due to a visual-spatial deficit”. In practice, this means the student has trouble with the layout of writing – letters might drift off the line, spacing is irregular, or the overall page organization is jumbled. The same poor visual-spatial skills that make it hard to judge numerical magnitudes or shapes can lead to illegible handwriting and difficulty copying text. Essentially, if the brain’s visual mapping system is underdeveloped, both placing numbers in the right place and writing letters neatly become challenging.
Working memory and sequencing
Both math and writing require holding sequences in mind – whether it’s the steps of a calculation or the sequence of letters in a word/sentence. A common thread is that many dyscalculic learners have weak working memory, and this also affects written expression. For example, when writing a sentence, a student needs to remember the spelling of words while also planning the next ideas – a task requiring mental juggling. If their working memory capacity is low, they may write slowly, omit letters or words, or lose track of their thoughts (hallmarks of dysgraphia). Similarly, sequential processing difficulties can make it hard to carry out multi-step math procedures and also to execute the motor sequence of forming each letter in a word. The neurological inefficiencies in memory and sequencing manifest as both math errors (losing track of steps) and writing errors (disordered or incomplete writing).
General processing speed or attention
Some children with dyscalculia and dysgraphia share a slower processing speed or mild attentional difficulties (even separate from ADHD). If the brain processes visual information slowly, it impacts the quick recognition of numbers and the quick production of written text. This is why interventions often note improvements in both areas once the underlying cognitive skill is addressed. Importantly, the co-occurrence of dyscalculia and dysgraphia does not mean the child is “lazy” in multiple subjects – rather, it underscores that the brain processes required for math and writing have commonalities. For instance, both rely on integrating visual information with motor output (eye-hand coordination). Neuropsychological studies suggest that when a child has a deficit in such integration, it can show up in various academic skills. The strong correlation and frequent co-diagnosis of dyscalculia and dysgraphia reflect these shared neural substrates. Recognizing this overlap can actually help in intervention – for example, therapies that improve visual-spatial reasoning or working memory can benefit both math and handwriting skills.
Next up: Visual skills behind the struggles
What vision has to do with math
Math isn’t just about numbers—many kids with dyscalculia also struggle with visual processing. Learn how visual perception and spatial awareness affect number sense.