The 2013 PBS KIDS Transmedia Math study is an important part of the multiyear Ready To Learn summative evaluation conducted by the Education Development Center, Inc., (EDC) and SRI International (SRI) for the Corporation for Public Broadcasting (CPB) and PBS. This study utilized a randomized controlled trial (RCT) design to explore how technology and educational transmedia resources can enhance prekindergarten mathematics teaching and learning in preschools, preparing children, especially those who may be at risk for academic difficulties due to economic and social disadvantages, for kindergarten. The study lasted ten weeks and focused on supporting the growth of mathematics skills such as counting; subitizing; recognizing numerals; recognizing, composing, and representing shapes; and patterning. The design included three conditions: PBS KIDS Transmedia Math Supplement, Technology & Media, Business-As-Usual. The PBS KIDS Transmedia Math Supplement condition provided classrooms with digital tools (i.e., interactive whiteboards and tablet computers), instructional support (i.e., coaches), and a structured curriculum supplement that supported teachers in integrating PBS KIDS transmedia into regular classroom instruction and routines. The Technology & Media condition provided the same digital tools and instructional support as the PBS KIDS Transmedia Math Supplement condition, but did not provide a curriculum supplement for guiding the selection and use of the digital resources. Teachers in the Business-As-Usual condition continued to engage in their typical mathematics activities without the addition of any digital tools, instructional support, or curriculum supplement. (author abstract)