Interview with Dr Hans van Luit

Interview with Dr Hans van Luit, Professor of Dyscalculia at the Utrecht University in the Netherlands. The Netherlands is one of the few countries where dyscalculia has been officially recognized. Since 2012 psychologists follow guidelines from the Dyscalculia Protocol for a diagnosis of dyscalculia, published by Dr van Luit and his team. The protocol contains guidelines and several detailed case studies. Students who receive an official diagnosis receive support in school as well as accommodations for exams. Dr van Luit and his team have also designed an evidence-based math intervention for students at risk for dyscalculia.

1) What are the three criteria used to diagnose dyscalculia in the Netherlands?

Criterion 1: determining the presence and severity of the math problem.

Criterion 2: to determine the math problem related to the personal abilities There is a significant discrepancy with respect to what can be expected of the student, based on their individual development.
a) Their cognitive level can be determined by an intelligence test. It is not possible to determine dyscalculia when the student has an intelligence score of 70 or below. In case the total IQ-score is between 71 – 85, diagnosing dyscalculia has to be done with caution. Mathematics requires a complex skillset, which relies on higher cognitive functions. Therefore, it is not realistic to expect from children with an IQ-score between 71 – 85 to develop and achieve the same math level as their peers with an average IQ-score.
b) An analysis of the student’s school history should reveal a specific low progress in mathematics. In the event that the performance in other learning areas is also low, it likely indicates a general learning problem or a broad learning disorder.
c) Mathematical problems of gifted children often get noticed later than usual.
d) In case a student has a comorbid disorder (ADHD for example), his or her math performances have to be considerably lower than usually expected of children with the disorder. For other comorbid disorders like dyslexia, autism and dyspraxia such lower scores are not necessary.

Criterion 3: to determine persistence of the mathematical problem

There is a persistent problem in learning mathematics. To determine the persistency of the problem, the structural and specialized help a student received in mathematics is investigated. According to the model of ‘Response-to-Instruction’, didactic resistance can only be determined with great certainty, when the conditions on all three levels have been complied (Fuchs & Vaughn, 2012). A dyscalculia diagnosis can only be made if the student fulfills all 3 criteria.

2) How can we identify children who are at risk for dyscalculia or severe math difficulties at an early age?

There are several indicators. When parents talk about the development of their child who has a math problem, they often mention that their child at a young age (4 – 5 years old) lacks knowledge about numbers, symbols, precise counting of a small number of objects etc. So, the signs are already there at an early stage. Teachers in kindergarten mention that children who are diagnosed with dyscalculia at an older age, were weak performers on mathematics related tasks such as fluent counting forward and backwards, understanding early math vocabulary such as ‘fewer than, more, less’ and so on. Teachers in grades 1 and 2 mentioned they noticed a very low performance of that particular child in understanding the regular math instructions and very low results in math tasks and tests. The signs may appear earlier, but the diagnosis is only possible from grade 3 (Primary 3) onwards.

3) What is the best way to support students who have been diagnosed with dyscalculia, including accommodations in school?

An important part is to investigate the learning potential of a child. In this diagnostic process, the therapist is searching for the zone of proximal development (tasks which are not too difficult and not too easy for the child). This concept concerns investigating the level of mathematics at which an individual student can solve tasks independently, and how much and of what intensity a child needs help when the complexity of tasks is slightly enhanced. By offering help (using one or more five phases of help: offering more structure, decrease the complexity, offering verbal help, offering material help or modelling – demonstrate, associate, or copy – of the material help) the therapist discovers from which kind of instructions the child benefits the most.

The ease with which the student can reproduce the strategies after one or two weeks with similar tasks, is an indication for learning potential. For some children the taught strategies appear to be unfamiliar, even when the strategies have been practiced intensively. In that case their learning potential appears low. Other children are capable of reproducing the taught and practiced strategies with similar tasks, which indicates some higher potential. Furthermore, the therapist takes note of weak and possible strong characteristics of the child: for example, a weak verbal ability and an average visual ability. Subsequently, the therapist can teach the child to make a picture/model of the math problem to increase a better understanding, which makes it easier to solve this task. Another example, a child with dyscalculia who is weak in automatizing basic arithmetic such as 8+7 or 7×3 can benefit from support resources such as a strategy card or a calculator. All support which can help the child and that is allowed by school (and law) can be implemented, including the use of resources which compensate the lack of remembering facts and so on.

4) What is the most important message in your latest book ‘This is Dyscalculia’ (2018) that you think is crucial to know for practitioners, teachers and parents?

A diagnostic assessment to determine the individual deficits, an early intervention and professional guidance are pivotal in providing the best support for a student who has dyscalculia.


Fuchs, L. S., & Vaughn, S. (2012). Responsiveness-to-intervention; A decade later. Journal of Learning Disabilities, 45, 195-203.

Van Luit, J.E.H. Bloemert, J. Ganzinga, E.G. & Monch, M.E. (2012). Protocol Dyscalculie: Diagnostiek voor Deskundigen [Protocol Dyscalculia: Diagnosis for Professionals]. Doetinchem: Graviant Educatieve Uitgaven.


Dr Annemie Desoete

Dr Annemie Desoete (Belgium) is an expert in Early Numeracy Skills and Dyscalculia. She is currently a Professor at the Faculty of Psychology and Educational Sciences at the Ghent University in Belgium. She has extensive experience in research on early characteristics of learning disabilities, especially dyscalculia and dyslexia. In addition, she is conducting research on comorbidity with DCD and ASD. She has published several articles on Kindergarten studies related to early math.

Annemie Desoete has conducted several studies related to the early math skills of Kindergarten students and highlighted some early indicators for math learning difficulties; such as difficulties with counting, less spontaneous focusing on numbers, difficulties with subitizing, difficulties with seriation, classification and magnitude comparison. She also stressed the importance of math language, as many children with language delays also encounter difficulties in mathematics.

Opportunities to learn math at home and at school are vital for at-risk groups such as low-income families. Intensive and more explicit participation in adaptive educational games during Kindergarten years will be beneficial (Desoete & Baten (2017). Motivation and self-efficacy are equally important for math achievement, whereas math anxiety may hinder math development and should be addressed as early as possible.

Dr Desoete shared her recommendations on supporting students who have been diagnosed with dyscalculia, saying “believe in them and focus on ‘insight’. Early intervention by specialists, preferable in a one-to-one situation, that includes feedback, feedforward and provides clear and explicit instruction is crucial, as well as repeating and adding new insights that what is already known. Focus on autonomous motivation (give a choice, explain why) and metacognition.


In Belgium, dyscalculia has been officially recognized for a long time. Psychologists who have an expertise in learning disorders and professionals who have obtained a Masters in Special Education are qualified to provide a diagnosis for dyscalculia. “A diagnosis of dyscalculia can only be given if children meet all criteria, meaning that the disorder can only be diagnosed in elementary school based on severe difficulties mastering number facts or calculation persisting for at least six months despite the provision of interventions that target those difficulties” Desoete & Baten (2017).

The authors also mentioned that dyscalculia is more prevalent among students who have already been diagnosed with ADHD, dyspraxia (DCD) or dyslexia, especially when the students have severe spelling difficulties. However, some students can have ‘pure’ dyscalculia, and score high marks in other school subjects.

Dr Desoete has just published a new book ‘Succeeding with dyscalculia in higher education’ (Oct 2020) in which people with dyscalculia share the obstacles they had to overcome during their school years, but also the success stories. Tips are provided related to the next goal which is finding a job. Searching for individual strengths and simultaneously encouraging employers to be more open to discover the hidden potentials of students who have a mathematics disorder, the book provides a positive perspective on people with dyscalculia.




Desoete, A. & Baten, E. (2017). Indicators for a specific learning disorder in mathematics or dyscalculia in toddlers and in kindergarten children. Belgium Journal of Paediatrics, 19(2), 122-124.


Interview with Dr Daniel Ansari

Dr Daniel Ansari (Germany), is a Dyscalculia expert and currently Professor in Developmental Cognitive Neuroscience in the department of Psychology at the University of Western Ontario in Canada. He is also affiliated with the NIE/NTU in Singapore and visits regularly. He shared about his current research studies and emphasized on the importance of early screening for math difficulties:

1)You have been a visiting professor to the NIE/NTU in Singapore since 2017, why were you keen to take up this position?

There is a variety of reasons; it allowed me to collaborate with a number of researchers in Singapore who I have been in contact with over the years such as Kerry Lee and Rebecca Bull who both have unfortunately since left the NIE. Singapore obviously is a country that is very famous for its math education system, so I was keen to understand more about that. The overall ability to help the NIE to integrate more cognitive neuroscience into their research portfolio was also a big factor. The NTU has a new imaging centre CoNiC and to be able to do some work there and to train students and postdoctoral fellows there was a great opportunity.

From a personal point of view, it was an opportunity for my family to spend some time in a different country and to get to know a different country a little bit better. All of these things together, motivated me to help write the grant that eventually started the research project.

2)In your opinion, what has the field of neuroscience contributed to the enigma of dyscalculia during the last few years?

Unfortunately, not that much yet. I think the research literature on the neuro-correlates of dyscalculia is just not very solid yet. There are not enough studies, so one of the things we have done in Singapore and we are just analyzing the data, we have done a very large comparative imaging study of children with math difficulties. I am hoping that will contribute something. We know from brain-imaging now that children with and without dyscalculia look different in terms of brain activation and structure etc, but we need a lot more reliable data to make bigger inferences. In the imaging study there were about 30 participants and in the wider behavioural study we have got over a hundred students. So, we are going to be combining the behavioural and the brain imaging data to make better inferences. If you look into the literature, the samples sizes are like 8 or 12. So having 30, and we know they have been having math difficulties since they were 6 years of age, we have very good cognitive characterisations of these groups. That will allow us to interpret the imaging data in more meaningful ways as well. This is a field that is in its infancy compared to dyslexia for example.

3)Why is it important for students who have been diagnosed with Dyslexia or ADHD to be assessed for math as well?

I think it is critical actually. Because we know that learning difficulties co-occur. The co-morbidities rates are very high. It is very rare to encounter children who only have one learning difficulty; typically, they have more than one. It is important to look at the math problems for children who have dyslexia (or ADHD) for sure. Absolutely!

4)You recommend early screening for math difficulties, what age would this be?

What I recommend is that we look at early math just like we look at early reading. That we use better tools to identify kids who might be falling behind. I don’t think it is possible to diagnose dyscalculia when children are 3,4 or 5, but it is possible to catch children who might be lacking fundamental concepts. One of the things I feel very strongly about is in early Kindergarten we test whether children have an understanding of cardinality. Because we know there are huge individual differences, whereby some children have an understanding of the meaning of counting by the age of 2,5 and others by the age of 5. We also know that if these children aren’t caught, these gaps will persist and will grow larger. In my local school district, they screen all children using a phonological awareness screener, so why don’t we have something similar for numbers, we should. We can screen children as young as 4 or 5 for basic math concepts. That does not mean we can diagnose them; in fact, we should not diagnose them at that stage, but at least we can catch those that are falling behind.

5)How may math anxiety affect the performance in mathematics?

Math anxiety is one of those topics that has only recently caught the attention of researchers, I think teachers and educators have been aware of it for decades. The way in which we think that math anxiety influences your math abilities, or your ability to complete a math problem, is that when you are experiencing math anxiety you are ruminating about that. You are reflecting on your anxiety. It is taking part of your processing resources, so you can’t devote those resources to other tasks. Research proposed by Mark Ashcraft, quite a few years ago and has since gotten a lot of attraction, his notion is that when you have math anxiety and at the same time you are doing math, you are essentially doing two things at the same time. You try to deal with your anxiety, but you are also trying to do the math task. So, in that way, math anxiety really influences the processing of numerical and mathematical information, because it takes away some of the processing resources that you would otherwise dedicate to doing the task. What is important to know about math anxiety and math ability, is that they are only weakly related. This means you have students who have high math anxiety but are actually very competent at math, and students who have low math anxiety but are also very competent at math. So, you have both extremes, so that’s important to know there are students who experience math anxiety but it has nothing to do with their math ability.


6)Lastly, what are your favourite places to eat or visit in Singapore?

There are so many! One of my favourite places is Alexandra food court, there are several amazing places there; an amazing Chinese dumpling place and they have amazing soups there too and really good carrot cake. Other places hmmm, I like Pulau Ubin for the chili crab, and I really like the Satay by the Bay, near Gardens by the Bay, the food is really good! The food courts near the NTU where I sometimes went with my postdoc are amazing. Little India is fantastic too, I especially love North Indian food!

Dr Daniel Ansari has several educational videos on YouTube and stressed that “Dyscalculia is as common as dyslexia” in Understanding Dyscalculia (2017).