Annoyed with his dad, who demands that he be the first in his class, Zeca has an incredible adventure when he finds someone under his bed who is downcast and wants to leave behind what he really is: It is THE NUMBER 1, himself. Addressing the law of action and reaction, the author takes the wise, kind Queen Arith Metic from the Kingdom of Mathematics. She is going to help Number 1 understand the importance of his role in the group he belongs to. The story flows in a creative and attractive way for the young reader, dealing with the sentiment of solidarity and the capacity for individual appreciation.