The name of Zoltan P. Dienes (1916- ) stands with those of Jean Piaget, Jerome Bruner, Edward Begle, and Robert Davis as a legendary figure whose work left a lasting impression on the field of mathematics education. Dienes' name is synonymous with the multibase blocks that he invented for the teaching of place value. Among numerous other things, he also is the inventor of algebraic materials and logic blocks, which sowed the seeds of contemporary uses of manipulative materials in instruction. Dienes' place is unique in the field of mathematics education not only because of his theories on how mathematical structures can be effectively taught from the early grades onwards using manipulatives, games, stories, and dance (e.g., Dienes, 1973, 1987), but also because of his tireless attempts for over 50 years to inform school practice through his fieldwork in the United Kingdom, Italy, Australia, Brazil, Canada, Papua New Guinea, and the United States. Dienes' theories on the learning of mathematics have influenced many generations of mathematics education researchers, particularly those involved in the Rational Number Project (http://education.umn.edu/rationalnumberproject/), and more recently those working in the models and modeling area of research. Dienes championed the use of collaborative group work and concrete materials, as well as goals such as democratic access to the process of mathematical thinking, long before the words constructivism, equity, and democratization became fashionable. In this rare interview, Dienes (see Figure 1) reflects on his life, his work, the role of context, language, and technology in mathematics teaching and learning today, and on the nature of mathematics itself.