Related Experiment Video
Updated: May 26, 2026

Multimedia Battery for Assessment of Cognitive and Basic Skills in Mathematics (BM-PROMA)
Published on: August 28, 2021
Developmental Changes in the Profiles of Dyscalculia: An Explanation Based on a Double Exact-and-Approximate Number
Marie-Pascale Noël1, Laurence Rousselle
1Center of Cognitive Neuroscience, Institute of Psychology, Catholic University of Louvain Louvain-la-Neuve, Belgium.
Abstract:
Studies on developmental dyscalculia (DD) have tried to identify a basic numerical deficit that could account for this specific learning disability. The first proposition was that the number magnitude representation of these children was impaired. However, Rousselle and Noël (2007) brought data showing that this was not the case but rather that these children were impaired when processing the magnitude of symbolic numbers only. Since then, incongruent results have been published. In this paper, we will propose a developmental perspective on this issue. We will argue that the first deficit shown in DD regards the building of an exact representation of numerical value, thanks to the learning of symbolic numbers, and that the reduced acuity of the approximate number magnitude system appears only later and is secondary to the first deficit.
Related Concept Videos
Learning Disabilities
Dyslexia
Dyslexia is a...
Accuracy, limits, and approximation
Accuracy is defined as the closeness of the measured value to the true or actual value. In engineering mechanics, repeated measurements are taken during theoretical or experimental analyses to ensure that the result is precise and accurate.
The accuracy of any solution is based on the...
Quadratic Equations in the Complex Number System
Complex Numbers
Linearization and Approximation
Approximate Integration

