In which class we can discuss with schoolboys the problems of nanotechnology?
To understand the problems of modern technologies, including the production ofmicrochips, we need to know the phenomena of interference and diffraction of light. These phenomena are studied only in 11-th class, and only the most simple examples. The article gives the methodology of teaching the phenomena of interference and diffraction of light by students in 8-th class on the basis of vector diagrams, using a numerical method for calculating the diffraction patterns. Results of the calculation of diffraction by a slit and indicate the possibility of experimental verification of the calculations.