Technology has become a major force in developing curricula and educational practice in mathematics education internationally. While many technologies are important in affluent developed countries, the hand-held calculator continues to be the technology most likely to be available to students when and where they need it. Modern calculators have been designed to support secondary school mathematics education at various levels, including much more powerful ways than merely providing numerical answers to arithmetical questions, and continue to be one of the few technologies designed expressly for educational purposes. In light of economic realities, it is argued that calculators provide the most affordable mechanism for developing countries to provide students with access to technology in mathematics. A major element of calculator use involves individual exploration of mathematical ideas, for which a personal technological device is ideally suited. Support for the work of teachers is recognised as critical for integrating technology into the mathematics curriculum. (Contains 5 figures.)