Geometrical awareness enhances numeracy in children with Trisomy 21

Background: Studies on cognition in children with Down Syndrome (Trisomy 21) have described poor performance manipulating numbers. Elisabetta Monari's (2002) research suggest that considering mathematics as a universe of exploration beyond written arithmetic can offer them an opportunity for “human flourishing” (Su 2020). Geometry offers a suitable starting point. Objective: Exploring the use of geometrical activities for introducing children with T21 to integer and rational numbers. Design: A series of 7 workshops were designed to convey arithmetic concepts (counting, comparing and measuring) through plane geometry activities. Setting and Participants: Seven children aged 9 to 13, who had already completed a 3-year work on geometry, participated in the workshops held at the venue of the Spanish association Sesdown in Zaragoza, in leisure time. Data collection and analysis: Raw data consisted of 1) written reflections of lived experience (Van Manen 1990) by all adults participating in the experiment, following a shared protocol observation guide; 2) photographs; and 3) edited short videos. Results: Understanding of counting, cardinality, multiplication, measure and simple fractions was enhanced by previous geometrical conceptions, which came to the forefront and were reinforced. Moreover, activities enhanced speech. Cheerful engagement and increased awareness was also observed. Conclusions: The integration of arithmetic and geometry helps children with T21 to enter the mathematical world with understanding and pleasure. Primary school mathematics focuses on written arithmetic, but geometry is hidden in many educational aids and models. Explicit geometrical work can help inclusion of all children in mathematics school lessons.