It is the content of mathematics wide angle in unit 5 of sixth grade mathematics of People's Education Press. "Dove nest problem" is a form different from the previous mathematics learning content. Through the study of "pigeon nest problem", we can cultivate good logical thinking ability.

This mathematical problem is the principle of mathematical combination put forward by German mathematician Dirichlet. Pigeon hole principle says: If you put 10 apples in nine drawers, there will always be at least two apples in one drawer. The principle of pigeon nest is that six pigeons fly into five pigeon nests, and there is always a pigeon nest that flies into at least two pigeons.

In fact, the pigeon hole principle is the same as the pigeon nest principle, and the law is the same, so the solution is the same.