"Scratch" is a media-rich digital environment that utilises a building block command structure to manipulate graphic, audio, and video aspects. It incorporates elements of Logo including "tinkerability" in the programming process. In "Scratch" students use geometric and measurement concepts such as coordinates, angle, and length measurements. It facilitates creative problem solving and logical reasoning, and encourages collaboration. In this article, the author describes how "Scratch" can be used to design games to develop mathematical concepts. He examines the ways mathematical thinking emerges when children work with "Scratch," an interactive, programming language. He describes how a class of Year 6 students used "Scratch" to design an activity for their Year 1 "buddy" class and considers how this facilitated an authentic problem-solving process. The ways their mathematical thinking emerged through this process are outlined, along with further suggestions for using "Scratch" in classroom situations. (Contains 4 figures.)