The document describes an enrichment activities professional development program presented by Dr. Yeap Ban Har of Marshall Cavendish Institute in Singapore. It discusses using enrichment to promote reflective thinking in mathematics, including differentiation, acceleration, enrichment for advanced and all learners, and anchor tasks. It presents a three-part lesson structure of anchor task, guided practice, and independent practice. It provides examples of posing questions as enrichment and questioning assumptions as enrichment during mathematics lessons.