There have been several workshops in the Lorentz Center and in Delft, dedicated to number theory, dynamical systems, and their applications. It all started with the workshop on Numeration in 2010 in the Lorentz Center, which has been recurring once every year in various forms. This workshop is another one in that line. It is dedicated to number theory, dynamical systems and quasicrystals. Which brings us to the aim of the workshop: to establish cooperation between researchers in various fields and various locations -- leading to joint work and ideally taking it to the next level in the form of joint grant proposals.