Inservice teachers need ways to gain an integrated knowledge of content, pedagogy, and technologies that reflects new ways of teaching and learning in the 21st century. This interpretive study examined inservice K-8 teachers' growth in their pedagogical content knowledge (PCK) toward technology, pedagogy, and content knowledge (TPACK) in an online graduate course designed for integrating dynamic spreadsheets as teaching and learning tools in mathematics and science. With the lens of four TPACK components (Niess, 2005), the analysis describes teachers' development from recognizing to accepting, adapting, and exploring TPACK levels. Implications and recommendations for the design of future professional development courses and continuing research are identified to support inservice teachers' knowledge growth for teaching with technologies.