Number Dyslexia; Math Dyslexia; Dyscalculia in Children

math-2Doing poorly in school traumatizes children. Parents who watch their children struggle with schoolwork daily understand this better than anyone.

But even parents may not realize just how lasting this trauma can be. Panicker and Chelliah (2016) concluded that children with learning disabilities exhibit chronically elevated stress levels, and that stress is disruptive to brain development and learning. The trauma of doing poorly at school frequently results in negative thoughts that can be deep and lasting (Sapolsky, 2004). If left unchanged, a negative self-image can detrimentally impact a child’s life well beyond school.

Dyslexia is a well-known learning disorder that affects your ability to read, spell, write, and speak. Although lesser known than dyslexia, number dyslexia or math dyslexia — better known as dyscalculia — is equally common and can be a debilitating problem in school and later life. The term “dyscalculia” comes from Greek and Latin and means “counting badly.” The prefix “dys-” comes from Greek and means “badly.” The root “calculia” comes from the Latin “calculare,” which means “to count.”

Table of contents:
  • What is number dyslexia, math dyslexia or dyscalculia?
  • How long have people been aware of dyscalculia?
  • How common is number dyslexia or dyscalculia in children?
  • What are the symptoms of number dyslexia or dyscalculia in children?
  • Why does math matter?
  • What causes number dyslexia or dyscalculia in children?
  • How can children with number dyslexia or dyscalculia be helped?
  • How can Edublox help?

  • What is number dyslexia, math dyslexia or dyscalculia?

    Number dyslexia or math dyslexia — better known as dyscalculia — refers to a wide range of persistent and extreme difficulties in math, including weaknesses in understanding the meaning of numbers and difficulty applying mathematical principles to solve problems. It is the most widely used term for disabilities in arithmetic and mathematics. Dyscalculia is not the same as the ordinary experience of “being bad at math.” Many people may find trigonometry difficult. Dyscalculics may be unable to solve simple problems such as 7+2 or 5×3.

    The math work of a 9-year-old with dyscalculia.

    Sometimes the term acalculia is used to refer to a complete inability to use mathematical symbols, while the term dyscalculia is reserved for less severe problems in these areas. 

    The term developmental dyscalculia may be used to distinguish the problem in children and youth from similar problems experienced by adults after severe head injuries. Developmental dyscalculia is a specific learning difficulty manifested by failure to achieve adequate proficiency in arithmetic despite normal intelligence, sufficient scholastic opportunites, emotional stability, and sufficient motivation.

    Some researchers propose that the scientific community should differentiate between primary and secondary developmental dyscalculia. Primary developmental dyscalculia is characterized by a severe deficit in numerical or arithmetic functioning caused by different underlying biological factors. Secondary developmental dyscalculia denotes individuals whose impaired numerical capacity can be explained entirely by non-numerical impairments, such as attention or working-memory processes (Kaufmann et al., 2013; Price and Ansari, 2013).

    How long have people been aware of dyscalculia?

    No one seems to know when the word “dyscalculia” came to life — the earliest we have come across is an advertisement in the New York Times from May 1968 (see below). We know, however, that researchers have used other words for a disability in math since the 1800s: arithmetic disability, arithmetic deficit, mathematical disability, and so on. The media has been using words like digit dyslexia, number blindness, and math dyslexia.

    Research into dyscalculia is very much in its infancy. Despite the importance of numeracy, dyscalculia has received little attention, and its familiarity with the general public is relatively low. Between 2000 and 2010, the NIH spent $107.2 million funding dyslexia research but only $2.3 million on dyscalculia (Butterworth et al., 2011).

    How common is number dyslexia or dyscalculia in children?

    Many people assume that the term learning disability refers to a reading disability. One often hears the saying, “A learning problem is a reading problem.” This, however, is not true. Among students classified as learning disabled, arithmetic difficulties are as prevalent as reading problems. McLeod and Crump found that about one-half of students with learning disabilities require supplemental work in mathematics.

    According to the British Dyslexia Association, dyscalculia and dyslexia occur both independently of each other and together. Research suggests that 40-50% of dyslexics show no signs of dyscalculia. They perform at least as well in math as other children, with about 10% achieving at a higher level. The remaining 50-60% do have difficulties with math. Best estimates indicate that somewhere between 3% and 6% of the population are affected with dyscalculia only — i.e. people who only have difficulties with math but have good or even excellent performance in other areas of learning.

    What are the symptoms of number dyslexia or dyscalculia in children?

    We can easily perceive the difference between two and three items through subitizing. But as the number of items increases, we resort to counting to arrive at an accurate total (Sousa, 2015).

    Poor number sense and subitizing are two of the core deficits in dyscalculia.

    Number sense refers to a person’s ability to use and understand numbers. People with good number sense understand how numbers relate to one another and are flexible in the approaches and strategies they use to perform calculations. They will, for instance, see that 29 + 30 + 31 is the same as 3 x 30 and will quickly work out the answer.

    Clements (1999) describes two types of subitizing: perceptual and conceptual. Perceptual subitizing involves recognizing a number without using other mathematical processes, just as you did when looking at Boxes A and B. Conceptual subitizing allows one to know the number of a collection by recognizing a familiar pattern, such as the spatial arrangement of dots on the faces of dice or domino tiles.

    Most people can subitize up to six or seven objects. A child with dyscalculia may find this very hard and may need to count even small numbers of objects. For example, if they are presented with two objects they may count the objects rather than just know that there are two.

    Other dyscalculia symptoms include:

    • Poor understanding of the signs +, -, ÷ and x, or may confuse these mathematical symbols.
    • Difficulty with addition, subtraction, multiplication and division, or may find it difficult to understand the words “plus,” “add,” “add-together.”
    • Poor mental arithmetic skills.
    • May have trouble even with a calculator due to difficulties in the process of feeding in variables.
    • May reverse or transpose numbers, for example, 63 for 36, or 785 for 875.
    • Difficulty with conceptualizing time and judging the passing of time.
    • Difficulty with everyday tasks like checking change.
    • Difficulty keeping score during games.
    • Inability to comprehend financial planning or budgeting, sometimes even at a basic level, for example, estimating the cost of the items in a shopping basket or balancing a checkbook.
    • Inability to grasp and remember mathematical concepts, rules, formulae, and sequences.
    • May have a poor sense of direction (i.e., north, south, east, and west), potentially even with a compass.
    • May have difficulty mentally estimating the measurement of an object or distance (e.g., whether something is 10 or 20 feet away).
    • Extreme cases may lead to a phobia of mathematics and mathematical devices.

    Finger-counting per se is not a sign of dyscalculia, but rather a normal aid to the memorization of math facts and the learning of efficient calculating strategies. Persistent finger-counting, particularly for frequently repeated, easy calculating tasks, does indeed indicate a problem with calculation.

    Why does math matter?

    The effects of math failure during the years of schooling, as well as math illiteracy in adult life, can seriously handicap both daily living and vocational prospects. Whether in science, business, or daily living, we cannot escape the use of numbers. Every job, from the rocket scientist to the sheepherder, requires the use of math! No matter the country you live in, the language you speak, math is unavoidable and required knowledge.

    Having dyscalculia can lead to social isolation as a result of an inability to be at the right place at the right time or to understand the rules and scoring systems of games and sports. Some adults with dyscalculia never learn to drive because of the numerical demands of driving (Hornigold 2015). A large UK cohort study found that low numeracy was more of a handicap for an individual’s life chances than low literacy: They earn less, spend less, are more likely to be sick, are more likely to be in trouble with the law, and need more help in school (Parsons & Bynner, 2005).

    Franklin (2018) says children with dyscalculia are more prone to math anxiety than other children. The catch-22 with math anxiety is that these children are less likely to engage in math-related activities, and therefore they fall farther behind their peers in math skill development. Falling behind exacerbates a child’s level of anxiety, which in turn diminishes their desire to engage in mathematics. And so it goes.

    What causes number dyslexia or dyscalculia in children?

    Successful intervention is dependent on finding the cause or causes of a problem. Most problems can only be solved if one knows their causes. A disease such as scurvy claimed the lives of thousands of seamen during their long sea voyages. The disease was cured fairly quickly once the cause was discovered, viz. a vitamin C deficiency. A viable point of departure would therefore be to ask the question, “What causes dyscalculia?”

    If one twin has dyscalculia there is a 58% likelihood that his/her identical twin and a 39% chance that a non-identical twin will also be dyscalculic.

    While the environment plays a role — poor teaching or environmental deprivation, for example — there is strong evidence for a genetic basis. For example, if one twin has dyscalculia there is a 58% likelihood that his or her identical twin and a 39% chance that a non-identical twin will also be dyscalculic. The link also exists between dyscalculics’ parents and siblings: around half of all the first-degree family members of a dyscalculic also have dyscalculia (mothers, 67%; fathers, 41%; brothers, 53%; sisters, 52%), and 43% of the second-degree relatives. This prevalence is around tenfold higher than expected for the general population. However, there are no gender differences (Kadosh & Walsh, 2007). 

    Although some causes of dyscalculia have a genetic origin, and environmental factors play an important role, cognition mediates brain-behavior relationships and therefore offers a sufficient level of explanation for the development of principled interventions. We thus need to understand the cognitive difficulties that underpin math failure, regardless of whether their origin is constitutional or environmental (Elliott & Grigorenko, 2014).

    Mathematics consists of three aspects

    • Foundational skills:

    Research has shown that visual perception, visual memory, visuospatial memory, working memory, and logical thinking (which makes problem-solving possible) are foundational skills of math.

    Visual perception refers to the process of interpreting and organizing visual information. Visual perception is often subdivided into areas such as visual discrimination and visual memory. Visual discrimination involves the ability to attend to and identify a figure’s distinguishing features and details, such as shape, orientation, color, and size. Visual memory refers to the ability to remember a visual image.

    One hundred and seventy-one children with a mean age of 10.08 years participated in a study by Marjean Kulp et al. This study, conducted at the Ohio State University College of Optometry, was designed to determine whether or not performance on tests of visual perception could predict the children with poor current achievement in mathematics. Controls for age and verbal cognitive ability were included in all regression analyses because the failure to control for verbal ability has been a criticism of some literature investigating the relationship between visual and academic skills.

    Kulp et al. concluded, “poor visual perceptual ability is significantly related to poor achievement in mathematics, even when controlling for verbal cognitive ability. Therefore, visual perceptual ability, and particularly visual memory, should be considered to be amongst the skills that are significantly related to mathematics achievement.”

    Szűcs and team (2013) from the University of Cambridge, UK set out to compare various potential theories of dyscalculia in more than a thousand 9-year-old children. The researchers found that children with dyscalculia showed poor visuospatial memory performance. For example, they performed poorly when they had to remember the locations of items in a spatial grid. Dyscalculic children’s ability to resist distraction from irrelevant information was also weak. On a task where they had to choose which of two animals was larger in real life, they performed poorly when the real-life larger animal was smaller in its display size.

    Working memory difficulties have also been associated with developmental dyscalculia. Geary (1993) suggests that poor working memory resources not only lead to difficulty in executing calculation procedures, but may also affect the learning of arithmetic facts.

    • Mathematical skills:

    There are many things in mathematics that the learner must learn to do, like, for example, the skills of counting, adding and subtracting, multiplication and division, applying place value, fractions, understanding money, and reading time.

    • Knowledge:

    There is much in math that one simply has to know and therefore has to learn, for example, many terms, definitions, symbols, theorems, and axioms. These are all things that the learner must know, not things they must know how to do. A child, who does not know what a sphere is, will have to guess when confronted by twelve objects and the question, “Which of the above objects have the same shape as a sphere?”

    How can children with number dyslexia or dyscalculia be helped?

    Early intervention is essential to minimize the impact a learning disability can have on your child. If you recognize that your child is struggling with the spoken or written word, or with mathematics, no matter how old they are, you should intervene as soon as possible.

    Dyscalculia may have some serious implications for children if no intervention is provided. Primarily, dyscalculia may impinge on the emotional well-being of students. In a focus group carried out by Bevan and Butterworth (2007) with nine children with dyscalculia, many negative feelings were expressed related to the children’s constant failure in mathematics. The children reported that they felt left out, blamed themselves for not knowing how to solve a task, cried, as well as felt “horrible” and “stupid.”  In the long-term, math disabilities may negatively impact job opportunities and prospects in the workplace — even more than literacy difficulties (Bynner & Parsons, 1997).

    The following steps should be followed in dyscalculia intervention:.  

    • Intervention step 1

    It should be noted that learning is a stratified process. Certain skills have to be mastered first, before it becomes possible to master subsequent skills.

    To be a basketball player, a person first has to master the foundational skills, e.g. passing, dribbling, defense, and shooting. In the same way, in order to do math, a child first has to learn the foundational skills of math, like visual perception and visual memory. The child who confuses the signs +, -, ÷ and ×, may have a problem with visual discrimination of forms and/or visual discrimination of position in space. A child who has a poor sense of direction (i.e., north, south, east, and west) may have a problem with visual discrimination of position in space, etc.

    • Intervention step 2
    Learning is a stratified process. Certain skills have to be mastered before subsequent skills can be learned.

    The second step would be to master mathematical skills, which must be done sequentially. One has to learn to count before it becomes possible to learn to add. Suppose one tried to teach a child, who had not yet learned to count, to add. This would be impossible, and no amount of effort would ever succeed in teaching the child this skill. The child must learn to count first, before it becomes possible for him to learn to add.

    To be able to subtract, a child must also learn to count backward. Thereafter, skip counting should be introduced. Skip counting is important in the development of fluency in calculations, number sense and is the basis of multiplication and division. It is also important to help students move from calculating by counting by ones to using number facts. For example, instead of working out 12 + 4 by counting 12, 13, 14, 15, 16, students can immediately add 4, or possibly add 2 twice. This transition to using fluent number facts is key to success throughout school.

    • Intervention step 3.

    The third step would be to ensure that a learner catches up on the knowledge aspect of math.

    How can Edublox help?

    Edublox Online Tutor is an online platform that houses a range of products and services to improve various aspects of learning. Edublox’s math help consists of Development Tutor and Live Tutor and aims at

    • addressing the underlying shortcomings that interfere with math performance, such as poor visuospatial memory and logical thinking;
    • teaching math skills in a sequential fashion, such as counting and skip counting, adding and subtracting, multiplication and division, applying place value, fractions, understanding money, reading time, etc.;
    • and math knowledge.

    Below is an example of a child’s progress after receiving math help from Edublox. She was diagnosed with dyscalculia as well as dyslexia, ADHD, and low IQ. Click here to follow her journey to learning success.

    Below is another child’s progress after receiving math help from Edublox. She was diagnosed with dyslexia and acalculia. Click here to follow her journey to learning success.


    Book a free consultation to discuss your child’s math learning needs.

    The bottom line

    The only solution for a problem like dyscalculia is to address the causes. Until we have done that, the child will continue to struggle.


    Key takeaways

    Authored by Susan du Plessis (B.A. Hons Psychology; B.D.) who has 30+ years’ experience in the LD field.
    Medically reviewed by Dr. Zelda Strydom (MBChB) on May 21, 2021.
    Next review due: May 21, 2023.

    References and sources:

    Bevan, A., & Butterworth, B. (2007). The responses to maths disabilities in the classroom. Retrieved on April 17, 2020 from www.mathematicalbrain.com/pdf/2002BEVANBB.PDF.

    Butterworth, B., Varma, S., & Laurillard, D., (2011). Dyscalculia: From brain to education. Science, 332(6033), 1049-1053.

    Bynner, J., & Parsons, S. (1997). Does numeracy matter? London: Basic Skills Agency.

    Clements, D. H. (1999, March). Subitizing: What is it? Why teach it? Teaching Children Mathematics, 5, 400–405.

    Elliott, J. G., & Grigorenko, E. L. (2014). The dyslexia debate. Cambridge: Cambridge University Press.

    Franklin, D. (2018). Helping your child with language-based learning disabilities. Oakland, CA: New Harbinger Publications, Inc.

    Geary, D. C. (1993). Mathematical disabilities: Cognition, neuropsychological and genetic components. Psychological Bulletin, 114, 345–362.

    Hallahan, D. P., Kauffman, J., & Lloyd, J. (1985). Introduction to learning disabilities. Englewood Cliffs, NJ: Prentice Hall.

    Hornigold, J. (2015). Dyscalculia pocketbook. Alresford, Hampshire: Teachers’ Pocketbooks.

    Kadosh, R. C., & Walsh, V. (2007). Dyscalculia. Current Biology, 17(22).

    Kaufmann, L., Mazzocco, M. M., Dowker, A., von Aster, M., Göbel, S. M., Grabner, R. H., et al. (2013). Dyscalculia from a developmental and differential perspective. Frontiers in Psychology, 4(516).

    Kulp, M. T. et al. (2004). Are visual perceptual skills related to mathematics ability in second through sixth grade children? Focus on Learning Problems in Mathematics, 26, 44-51.

    Panicker, A., & Chelliah, A. (2016). Resilience and stress in children and adolescents with specific learning disability. Journal of the Canadian Academy of Child and Adolescent Psychiatry, 25, 17–23.

    Parsons, S., & Bynner, J. (2005). Does numeracy matter more? London: National Research and Development Centre for Adult Literacy and Numeracy, Institute of Education.

    Price, G. R., and Ansari, D. (2013). Dyscalculia: Characteristics, causes, and treatments. Numeracy 6(2).

    McLeod, T., & Crump, W. (1978). The relationship of visuospatial skills and verbal ability to learning disabilities in mathematics. Journal of Learning Disabilities4, 237–241.

    Sapolsky, R. M. (2004). Why zebras don’t get ulcers: The acclaimed guide to stress, stress-related diseases, and coping, 3rd ed. New York: St. Martin’s Griffin.

    Sousa, D. A. (2015). How the brain learns mathematics, 2nd ed. California: Corwin Press.

    Szucs, D., Devine, A., Soltesz, F., Nobes, A., & Gabriel, F. (2013). Developmental dyscalculia is related to visuo-spatial memory and inhibition impairment. Cortex49(10), 2674-2688. https://doi.org/10.1016/j.cortex.2013.06.007