Dyscalculia: understanding and supporting mathematical learning difficulties
Dyscalculia is a specific learning disorder that affects the acquisition of mathematical skills. Affecting 3 to 7% of children, it impacts number sense, calculation, logical-mathematical reasoning and problem solving. This comprehensive guide presents the scientific foundations, clinical manifestations and effective intervention strategies.
📋 In this article
What is dyscalculia?
Developmental dyscalculia is a neurodevelopmental disorder that specifically affects the acquisition of numerical and mathematical skills. According to the DSM-5, it is a specific learning disorder with impairment in mathematics, characterized by persistent difficulties in mastering number sense, arithmetic facts, calculation or mathematical reasoning.
This disorder is not the consequence of an intellectual deficit, sensory impairment, lack of instruction or adverse psychosocial factors. Children with dyscalculia have normal intelligence but mathematical performance significantly below what would be expected given their age, grade level and intellectual abilities.
🔬 Prevalence and comorbidities
Dyscalculia affects 3 to 7% of the population, with similar prevalence in boys and girls (unlike dyslexia). It is frequently associated with other disorders: dyslexia (30-70% comorbidity), ADHD (25%), developmental coordination disorder, and math anxiety (which can be both cause and consequence).
Number sense: neuroscientific basis
Number sense (or basic numerical cognition) is an innate ability, present from birth, that allows perception and manipulation of quantities in an approximate way. Neuroscience research has identified the intraparietal sulcus as the key brain region for quantity processing.
Components of number sense
| Component | Description | Example |
|---|---|---|
| Subitizing | Immediate perception of small quantities (1-4) without counting | Instantly seeing that there are 3 dots |
| Estimation | Approximate evaluation of large quantities | Estimating there are "about 50" people |
| Comparison | Determining which quantity is larger | 8 is greater than 5 |
| Mental number line | Ordered spatial representation of numbers | Placing 7 between 5 and 10 on a line |
In dyscalculia, one or more of these basic components may be deficient, compromising the construction of subsequent mathematical learning. This is why remediation must often return to the foundations of number sense.
Manifestations by age
In preschool (3-6 years)
- Difficulty counting in a stable and ordered manner
- Does not understand that the last number said represents the total quantity (cardinality)
- Difficulty comparing collections (more/less/same)
- Does not recognize small quantities without counting (no subitizing)
- Confusion with spatial terms (before/after, more/less)
- Difficulty with number rhymes
In elementary school (6-11 years)
- Difficulty memorizing arithmetic facts (addition and multiplication tables)
- Frequent errors in counting
- Confusion with place value (tens/units)
- Use of immature strategies (counting on fingers late)
- Difficulty with word problems
- Inversion of digits (12/21) or signs (+/-)
- Significant slowness in calculation
- Anxiety about mathematics
In middle school and beyond
- Difficulty with fractions, decimals, percentages
- Proportional reasoning problems
- Difficulty in geometry and measurement
- Inability to estimate if a result is plausible
- Difficulties in daily life: money, time, distances
Differential diagnosis
⚠️ What is NOT dyscalculia
Many children have difficulties in mathematics without being dyscalculic. We must distinguish:
- Mathematical difficulties related to inadequate or insufficient teaching
- Math anxiety that blocks performance (can coexist with dyscalculia)
- Secondary difficulties to a language disorder (comprehension of statements)
- Attention difficulties (ADHD) impacting concentration in calculation
- Global intellectual deficit affecting all learning
The diagnosis of dyscalculia requires a comprehensive neuropsychological assessment including evaluation of general intellectual level, cognitive functions (attention, working memory, executive functions) and specific mathematical skills. The speech-language pathologist can also perform a logical-mathematical assessment.
Different profiles of dyscalculia
| Profile | Main difficulties | Relative strengths |
|---|---|---|
| Number sense deficit | Estimation, comparison, quantity representation | Calculation procedures once learned |
| Procedural deficit | Learning and applying calculation procedures | Preserved number sense |
| Fact retrieval deficit | Memorizing tables, arithmetic facts | Conceptual understanding |
| Visuo-spatial deficit | Alignment, geometry, spatial representation | Mental calculation |
Remediation principles
1. Strengthen number sense
Before any work on calculation, it is essential to consolidate the foundations: subitizing, estimation, comparison, number line. Regular activities involving quantity manipulation, estimation games, number line placement help strengthen these foundations.
2. Use concrete manipulation
Respect the progression Concrete → Visual → Abstract. Use manipulative material (cubes, Cuisenaire rods, tokens, base-10 material) before moving to representations then symbols. This progression must be maintained even for older children if necessary.
3. Make strategies explicit
Children with dyscalculia do not spontaneously discover effective strategies. They must be explicitly taught: decomposition, bridging through 10, doubles and near-doubles, checking strategies. Verbalize reasoning aloud.
4. Gradually automatize
Once strategies are understood, aim for automatization through spaced repetition. The goal is to free up cognitive resources for more complex tasks. But beware: automatizing too early, before understanding, is counterproductive.
Practical strategies by domain
For numeration
- Use the number line as a permanent visual support
- Work with base-10 material (physical units, tens, hundreds)
- Play decomposition/recomposition games with numbers
- Verbalize place value: "42 is 4 tens and 2 units"
For calculation
- Teach calculation strategies explicitly (8+5 = 8+2+3 = 10+3)
- Use visual supports for tables (Pythagorean tables, cards)
- Allow compensation tools (calculator, tables)
- Work with fact families (3+4=7, 4+3=7, 7-3=4, 7-4=3)
For problem solving
- Use a structured methodology: read, identify data, understand the question, choose the operation, calculate, check
- Systematically diagram problems
- Work on key words (beware of traps: "more" is not always addition)
- Have students estimate the result before calculating
Our downloadable tools
🔢 Manipulable number line
Essential visual support for visualizing the number sequence, making comparisons and calculations by jumps. Several formats available (0-20, 0-100).
Download🧩 Decomposition cards
Cards illustrating the decomposition of numbers from 1 to 20, with representation in dots, fingers and numerical writing. Ideal for working on complements.
Download📝 Problem-solving aid
Methodological sheet with resolution steps, pictograms for operations and space for diagramming. Guides the child towards autonomy.
Download📊 Visual multiplication tables
Tables with visual representation in dot arrays to understand the meaning of multiplication. Aids memorization through images.
DownloadSchool accommodations
Students with dyscalculia can benefit from a PAP (Personalized Accommodation Plan) or a PPS (Personalized Schooling Project) depending on the severity of the disorder. Here are frequently recommended accommodations:
| Domain | Possible accommodations |
|---|---|
| Time | One-third extra time, reduction in quantity of exercises |
| Supports | Operation tables allowed, calculator, number line |
| Presentation | Spaced exercises, one operation per line, adapted font |
| Evaluation | Adapted scoring (valorize reasoning even if calculation is wrong) |
| Method | Allow personal strategies, finger counting |
Frequently asked questions
Yes, dyscalculia has a similar prevalence to dyslexia (3-7% of the population). However, it is much less known and less diagnosed. Mathematical difficulties are often wrongly attributed to a "lack of work" or the false idea that "math is not for everyone".
The diagnosis is generally made by a neuropsychologist after a comprehensive assessment. The speech-language pathologist can perform a logical-mathematical assessment and contribute to the diagnosis. The physician (neuropediatrician, school physician) validates the diagnosis and can direct towards accommodations.
Like other DYS disorders, dyscalculia is a lasting disorder but progress is possible with appropriate remediation. The goal is not to "cure" but to develop effective compensatory strategies and strengthen basic skills. With appropriate support, people with dyscalculia can develop sufficient mathematical functionality for their daily and professional lives.
Yes! The calculator is a legitimate compensation tool for children with dyscalculia, like glasses for a nearsighted person. It allows bypassing calculation difficulties to access mathematical reasoning. This does not mean abandoning work on calculation, but that the calculator can be used when calculation is not the main objective of the exercise.
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Discover all tools →Article written by the DYNSEO team in collaboration with specialized speech-language pathologists. Last updated: December 2024.