I used this piece (the Allegretto and Trio portions of which seem like two pieces) as sight reading exercises. I think these pieces, which sound jovial and robust, are much simpler than the book level. They were perhaps chosen to ease the student into the Fifth Grade Book without trepidation or intimidation. But when I started playing, it was clear that the technique wasn't really pushing my capabilities but lay well within them. So I sight-read a few times.
These are great melodies though. I rather like Schubert. From Serenade through Valse Sentimentale up to now (and looking forward to his Impromptus), he has never failed to please. Too bad he died so young... ah Schubert and Keats, parallel tragic romantics.