The Mathematics Content Authority List for K-6 (abridged) represents an attempt to list in one volume the mathematics concepts and skills currently taught in the elementary schools. The list consists of approximately 300 items involving concepts from number systems and numeration, sets, geometry, measurement of non-geometric quantities, and number patterns and relationships. Definitions, explanations, and examples are provided in an expanded version of this list. This list is used by the Pennsylvania Retrieval of Information for Mathematics Education System (PRIMES) Project to code elementary school mathematics textbooks and textbook activities for storage and retrieval. (RP)