The enhancement of primary sources for the history of mathematics in Italy was a determining element for the foundation of the scientific journal Bollettino di Storia delle Scienze Matematiche. In the teaching of mathematics, quoting meaningful passages from these sources can be a useful strategy to introduce arguments and concepts, or to raise awareness of historical development.
This talk presents a certain number of examples and suggestions, which go from the late Middle Ages and the Renaissance, to the first half of the twentieth century. Starting from original and recent research, it is possible to propose less usual themes connected to different mathematics topics and directed to different age groups, including: abacus mathematics and Archimedean tradition, the resolution of algebraic equations of third and fourth degrees, the pre-Newtonian systems of the world, the foundation of infinitesimal calculus, the science of waters and the origin of hydrostatic and hydrodynamic laws, new approaches in elementary geometry (fusionism, paper folding).