On page 12 we see a close up of Vladek as he pedals his exercise bike. What is the meaning of the numbers tattooed on his wrist? How does this single image convey information about the character?

Numbers (tatoos) were etched onto the prisoners wrists by the Nazia so they could keep track of them. This image conveys to the reader that Vladek is in fact a Holocaust.

The number on his wrist was 75113