This school is part of a series organized by the Rhone-Alpes node of CECAM. Previous editions were devoted to ''Soft matter'' (2011), ''Electronic structure'' (2012), ‘’DNA physics’’ (2013) and ‘’Cold atoms’’ (2014). The aim of the schools is to make the students familiar with the numerical techniques used in their field and to allow them to gain some practice by implementing some of these numerical techniques. Although the schools focus on methodological (algorithmic and computational) issues, a general theme in terms of physical applications is chosen within each session, so that the lectures can include physical examples of general interest to the audience. The theme for the proposed school is the "multiscale modeling of materials”. Numerical modeling of materials often requires linking different levels of description that operate on very different length and time scales, from quantum mechanics to continuum approaches. In the last two decades, a number of computational approaches have been developed to link these different descriptions, and to overcome the limitations in length and time that are intrinsic to the more microscopic approaches. The school will present an introduction to these techniques, with a focus on applications in the fields of nano and microstructured materials.