Ubiratan D’Ambrosio: Celebrating His Life and Legacy.

On May 12^th, Brazil and the world said goodbye to one of its biggest names in mathematics education, Ubiratan D’Ambrosio (December 8, 1932 – May 12, 2021). D’Ambrosio is recognized both throughout Brazil and internationally for having been the creator of ethnomathematics, a concept that acknowledges, values, and respects different mathematical ideas, procedures, and practices developed by the members of distinct cultural groups. D’Ambrosio analyzed the history of explanations of life and of natural evolution in different cultures. In the last years, his motivation had been the pursuit of peace, in all its four dimensions: individual, social, environmental, and military. In this paper we pay homage to Ubiratan D’Ambrosio, sharing our thoughts related to his personal, professional, and academic life. [ABSTRACT FROM AUTHOR]