The Italian numbers offer a systematic and in-depth overview of the data and statistical indicators available in our country on childhood and adolescence. They are the result of an extensive process of reconnaissance, collection and homogenisation of the available data produced by the institutions that deal with children and young people in various ways. The National Centre's notebooks bearing this title document the decades-long activity of collecting and organising data at national level. These volumes represent a valid tool for assessing the condition of children and adolescents, useful both to satisfy curiosity about these issues and as a basis for developing and planning targeted interventions. The data allow for territorial comparisons between regions and territorial divisions, as well as temporal comparisons up to the last available year (which varies according to the topic). As far as sources are concerned, the phase of verifying the reliability and quality, and therefore the scientific nature, of the data is one of the most important aspects. The ISTAT databases, those of the various ministries, the National Institute of Health and INAIL are the ones most frequently consulted.