Disorders of calculation (dyscalculia) would receive 3% of adults
Disorders of calculation, or dyscalculia, would receive 3% of adults in France according to a study conducted by INSEE based on the results of the survey information and Everyday Life in 2004. At 0.55% of the population would be severe dyscalculia.

Jean-Paul Fischer of the University of Nancy and Camilo Charron at the University of Rennes II conducted the study with 10,213 people. The identification of potentially dyscalculics was based on a criterion of difficulty in calculus and a criterion of difference between performance in calculus and French, for comparable tests.
Dyscalculia has less impact on daily life as dyslexia (learning disorder of language), the study said. According to Professor Fischer, the calculation itself (surgical techniques, written or mental) and arithmetic reasoning “are hardly needed in daily life”, through the use of calculators or computers and presentation documents . Many adults “circumvent the difficulty” to the point of not knowing for some of them, calculating anything at all!
The percentage of adults suffering from dyscalculia (3%) is significantly larger than that found in a 2007 study on children or preteens CE2 and sixth (1.1%). This could be due to the fact that children are subjected to several hours of work per week in mathematics, so that greater freedom of choice to enable some adults to avoid almost entirely any activity calculation.
The study shows that women are more likely to experience difficulties in calculating (4.31%) than men (3.13%). This trend can be explained “by the fact that women engage in sectors and occupations that require less math,” says Jean-Paul Fisher.
Dyscalculia decreases with the level of study: 8.7% of adults who were arrested before college dyscalculia are judged against 4% of those who have attained a high school education and 0.5% of those who have graduate.
Dyscalculia has its origin in a genetic disorder or congenital parts of the brain. It is quite often, but not always, accompanied by dyslexia.