This report contains a collection of papers on the status of the use of calculators in the schools of 16 countries. Each report summarizes trends and prevailing opinions about curricular implications of calculators; research activities; instructional practices; student attitudes; in-service activities; and general background on amount and type of use, projects, and other concerns. Also included are a synthesis of these national reports and a report of the International Working Group on Calculators from a meeting in January 1980. The report concludes with a list of selected references. The hope of the authors is that this document will answer some of the questions about the current status of calculator use for the following countries: Australia, Austria, Belgium, Brazil, Canada, Hong Kong, Ireland, Israel, Japan, New Zealand, Sweden, Switzerland, Thailand, United Kingdom, United States, and West Germany. (MP)