There is a paucity of research on Montessori Education’s impact on learning, especially in France. In this article, we present a study comparing the development of early number learning in preschoolers through Montessori Education with “conventional” education in France. Using a cross-sectional design and random assignment of children, we evaluated 131 French preschoolers (aged 5-6) enrolled at the same public school following either Montessori Education or conventional education over three years. Students were evaluated with the Woodcock-Johnson III (WJ-III) Applied Problems sub-test and a test designed by researchers in math education. The Montessori curriculum was associated with outcomes that were comparable to the conventional curriculum on math.