Educational Resource — Mathematical Secondary Education — UD.1- Natural Numbers

Natural numbers N = {1, 2, 3,... } appear to respond to the need to count of primitive man who, since ancient times, developed different numbering systems until the use of the current digits and their arithmetic were generalised. In this unit, the decimal numbering system and the basic operations with natural numbers are reviewed.
Two work proposals are presented that complement each other: exercises, problems and a real scenario where numerical approximations make sense and affect mental calculus.