How many children did Baron Von Trapp have in "The Sound of Music"?

"The Sound of Music" is a 1965 American musical drama film produced and directed by Robert Wise, and starring Julie Andrews and Christopher Plummer. The film is an adaptation of the 1959 Broadway musical "The Sound of Music", composed by Richard Rodgers with lyrics by Oscar Hammerstein II. The film's screenplay was written by Ernest Lehman, adapted from the stage musical's book by Howard Lindsay and Russel Crouse.

Based on the memoir "The Story of the Trapp Family Singers" by Maria von Trapp, the film is about a young Austrian woman studying to become a nun in Salzburg in 1938 who is sent to the villa of a retired naval officer and widower to be governess to his seven children. After bringing love and music into the lives of the family through kindness and patience, she marries the officer and together with the children they find a way to survive the loss of their homeland through courage and faith.

The real von Trapp family lost most of its wealth during the worldwide depression of the early 1930's, when the Austrian national bank folded. In order to survive, the family dismissed the servants and began taking in boarders. They also started singing onstage to earn money. In the film, the von Trapp family hike over the Alps from Austria to Switzerland to escape the Nazis, which would not have been possible; Salzburg is over two hundred miles from Switzerland. The von Trapp villa, however, was only a few kilometers from the Austria–Germany border.