Abstract
In this paper, the hypothesis that Developmental Dyscalculia (DD) is a characteristic of
Down syndrome (DS) is proposed. Implications for the hypothesis are addressed: If it were
to be confirmed that DS implies DD, what would be the consequences for the mathematics
education of learners with DS? The use of prosthetic devices to overcome the impaired
calculation capabilities of the brain is essential. Fortunately, electronic calculating devices
are readily available. Their routine use opens the possibility of studying areas of
mathematics that were once inaccessible.