It’s March 21, the first day of spring, and Mr. 1 leaves the calendar to venture into the city.
He will introduce us to many occasions where numbers are indispensable.
So important, yet so simple: they are infinite, but only ten digits are needed to build them all!

“Le avventure del Signor 1” is a book written by Anna Cerasoli and illustrated by me for Feltrinelli kids.