This article investigates the perception of students in the first year of high school in relation to their own body language, while mathematically they conjecture a way to improve their performance in an electronic bowling game, which uses body sensors for own actions of the game. Interactions were performed by a group of four students from a public school in Brazil, in order to perform mathematical activities with the Sports game on Xbox One with Kinect. Mathematically, the students discussed issues related to angulation, velocity, position relative to an axis and correlated to their digital being (game avatar) controlled by their biological body. In this sense, we are drawing up on embodied cognition articulated with the conceptions of perception and body-proper arising from the phenomenological view discussed by Merleau-Ponty. We understand that students' perception is shown by the acts of being-with, thinking-with and knowing-doing-mathematically-with-Digital-Technologies. Nevertheless, the perception of the body-proper opens up horizons of knowledge constitution that are not commonly seen in the mathematics classroom.