Small Change for Stuart by Lissa Evans

10-year-old Stuart Horten is often mistakenly thought to be much younger because of his small stature. It isn't easy for him to make new friends when his family moves to a different part of England, but Stuart is a pretty good at amusing himself. He is not quite as good at dodging the nosy triplet girls who live next door.

When Stuart learns that his great-uncle Tony used to live nearby, that he was a magician and inventor, and that he disappeared under mysterious circumstances, Stuart's summer is suddenly much more interesting. Magic, mystery and a very strange adventure await.

Lissa Evans' Small Change for Stuart would make an excellent family read-aloud.