Dr Sc in Mathematics, holding currently the position of Senior Professor of Mathematics at The Universidade Federal de São Carlos, BRAZIL. Work with Teacher Education in Mathematics at all levels, at the Graduate Program for Teachers and Continuing Education Projects for Teachers. Research areas: Geometry, Transition between Arithmetic and Algebra, Use of Technology (software and hand-held instruments) in Teaching/Learning, Lesson Study, and Singapore Mathematics, as main interest. Former Member at large of ICMI- EC (2013-2020), elected vice-president for CIAEM-IACME for 2024-2027.