Acquired vs Developmental Math Difficulty
One review uses "acalculia" for calculation trouble after a brain injury or illness (Ardila and Rosselli, 2002). In ICD-11, "developmental acalculia" leads to the same code as developmental dyscalculia. So "acalculia" is used both ways. To us, the developmental kind is about learning math, not losing it. Our position is that a lost skill goes to a doctor first.
Two names for math trouble
Dyscalculia describes lasting difficulty with number and calculation, out of step with the rest of a child's learning. In our view, the word tells you what is hard more than why.
A pediatric review calls developmental dyscalculia "a very heterogeneous disorder" (Kucian and von Aster, 2015). It says that makes shared criteria for diagnosis hard to set. We could read only the summary of that review.
To us, the developmental kind is about learning math, not losing it.
What one review means by acalculia
One review looks at calculation trouble of both kinds (Ardila and Rosselli, 2002). It uses "acalculia" for trouble that comes after a brain injury or illness. It treats developmental dyscalculia as a different thing. That review is mostly about adults with a brain injury. We could read only its summary.
Our position is that math lost after a brain injury goes to a doctor.
How ICD-11 uses the words
ICD-11 is the World Health Organization's list of medical codes. ICD-11 uses the name "developmental learning disorder with impairment in mathematics" for one code. In ICD-11, "developmental dyscalculia" leads to that code. So does "developmental acalculia". The word "acalculia" is used both ways. In our view, "acalculia" on its own does not tell you which kind is meant.
"Disorder" is the manuals' word, not ours for a child. A listing does not mean any one child has this trouble, or qualifies for help.
When a child loses a math skill
Some children could do something and now cannot. That is different from a child who has not built the skill yet. Our position is that a lost skill goes to a doctor first. In our view, make that appointment soon. We cannot tell you why a skill was lost. Tell the doctor what math your child could do before, and what is different now.
In our view, the first step is usually to work out what is hard. The exception is a skill that was there and has gone. Our position is that a lost skill goes to a doctor first, not a tutor.
Common questions from parents
What is acquired dyscalculia?
One review we hold uses another word for it. That review looks at two kinds of calculation trouble (Ardila and Rosselli, 2002). It uses "acalculia" for trouble that comes after a brain injury or illness. That review is mostly about adults with a brain injury. We could read only its summary. Our position is that math lost after a brain injury goes to a doctor.
What does developmental dyscalculia mean?
Dyscalculia describes lasting difficulty with number and calculation, out of step with the rest of a child's learning. In our view, the word tells you what is hard more than why. To us, the developmental kind is about learning math, not losing it. A pediatric review calls developmental dyscalculia "a very heterogeneous disorder" (Kucian and von Aster, 2015). We could read only the summary of that review.
What is the difference between acalculia and dyscalculia?
One review looks at two kinds of calculation trouble (Ardila and Rosselli, 2002). It uses "acalculia" for trouble that comes after a brain injury or illness. It treats developmental dyscalculia as a different thing. That review is mostly about adults with a brain injury. We could read only its summary. ICD-11 is the World Health Organization's list of medical codes. In ICD-11, "developmental acalculia" leads to the same code as developmental dyscalculia. So "acalculia" is used both ways. A code in ICD-11 does not mean any one child has math trouble, or qualifies for help. In our view, "acalculia" on its own does not tell you which kind is meant. Our position is that a lost skill goes to a doctor first, not a tutor.