2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/66185In this short survey we look at a few basic features of p-adic numbers, somewhat with the point of view of a classical analyst. In particular, with p-adic numbers one has arithmetic operations and a norm, just as for real or complex numbers.5 pages, latex-2e. Minor changesClassical Analysis and ODEstext