To each his own mania - Lycée Arago (Perpignan)

Titre du sujet
To each his own mania
Établissement
Lycée Arago (Perpignan)
Année
2017-2018
Résumé
You are fond of counting, it is almost a mania. When you see a number, you add its digits up and, if this sum divides the number you started with, you feel good! How often does it happen?
Mots clés