Following in the Footsteps of Pythagoras. Magic Squares and Magical Numbers

In the continuation of the collection "in the footsteps of Pythagoras", Schepan Elensky talks about the poetry of numbers: incredible results of multiplication, tricky divisions and amazing symmetries. Various operations, tricks and jokes with numbers are no less entertaining than logical tasks and puzzles.
A few millennia ago, people, fascinated by the secret numbers, made magic figures of them. Their amazing properties give rich material for entertainment and training of the mind.
No less useful gymnastics of the mind is the solving of the secrets of illusions and the search for error in paradoxical reasoning. The clarification of optical illusions and witty sophisms lays and strengthens logical thinking.
It is difficult not to succumb to the charm of mathematics when an experienced and knowledgeable guide opens it!
For secondary school age