Data collection, organization, and analysis are indispensable means of seeking solutions during the process of inquiry. Representations (called inscriptions by some educators) including graphs, tables, photographs, and equations are powerful ways of arranging and displaying data in visual form. This study aims to analyze quantitatively the use of representations by Key Stage 2 (KS2) students in extra-curricular science inquiry projects. The reports from 145 science inquiry projects entries in a primary science exhibition in Hong Kong were studied. A total of 22 projects were awarded Outstanding; 46 were awarded Merit; and 77 were awarded Consolation by the exhibition judges using well-established scoring rubrics and procedures. The ability to use different types of representations and the representational practices were studied across the three award classes. Levels of abstraction and functionality (constructing, interpreting, reasoning, and presenting) were determined for the representation types and practices demonstrated in the reports. The findings indicate that the highest level projects (judged Outstanding) tended to exhibit a higher frequency and more diverse use of representations. In addition, the three award levels also displayed different patterns of representational practices.