Design learning requires a specific ability to handle versatile digital instruments mentally and physically, in addition to drawing skills. Several tools are used during the design activity phase to search for information (Web), realize representations (2D, 3D), organize and state processes (word processing), and shape artifacts with " operative images " (image processing). Yet, in the current French design and technology (D&T) curriculum, the digital technologies are taught by applied arts and mathematics teachers who are not expert practitioners. We intend to understand the place of digital tools as 'instruments' within design activity by using underpinned activity theory (Engeström, 2011; Lebahar, 2007; Ochanine, 1966; Vygotsky, 2012) and ergonomics’ studies (Safin & Leclercq, 2009). An attempt is made to bring the didactics of D&T (de Vries, 2008; Ginestié, 2013), mathematics (Balacheff, 2010; Gueudet & Vandebrouck, 2009), and TPACK (Koehler et al., 2014; Voogt et al., 2013) together for this analysis. We sought to determine the how, what, when, and why D&T teachers can teach using digital technologies. We also tried to show that digital technologies can enhance teaching technology, if: – the tasks the teacher has prescribed are relevant to the D&T objectives in high school, – the teacher has the knowledge and skills to use technology, – the tools’ functions can be taught as not “magical” instruments, – an “interdisciplinary instrumental orchestration” is made, and – 2D or 3D representations lead to a new “drawing space”. Using the technological and pedagogical content knowledge (TPACK) research, the present research was based upon a curriculum analysis of the French D&T high school diploma (the STD2A baccalaureate) and upon four criteria presented by Angeli and Valanides (2009): identifying the learning objectives, selecting content, planning didactical material, and designing the learning environment.