Can anyone help me find a book about a young boy genius/savant trying to escape Germany?

[lobster_robster]

I remember reading a story as a child about a young boy genius/savant who is trying to escape Germany during WW2. The German's want him because his mother taught him how to memorise a great deal of secret codes and numbers.

I remember it was a condensed book in one my father's Readers Digest compilation books.

I would love to read it again or at least know the name!

[anniebird]

It is called "Daddy" written by Loup Durand.