ABANDONED. Children's Chapter book. Puzzles in a parallel world accessed by a portal in a beach cave, found by small group of kids on a field trip. Read 2004-2005.

[Sara]

What the story is about:
A class full of kids arrives to the beach area on a field trip, probably a picnic, and a small group wanders off down the beach and ends up inside of a cave. In the cave, they discover a portal and proceed through it into a (parallel?) new world. In this world, the group faces many obstacles in the form of logic and math puzzles that can be used in a classroom setting for the children to work along with the book.
I believe the first puzzle involved them crossing a river with a current in a sailboat, teaching about vectors and the Pythagorean theorem. Later chapters may include scaling a mountain both up and down. The last set of puzzles were approximately 7 walls, each with a gate only opened by a puzzle. I think if the children solved a puzzle wrong the gate was supposed to be locked for a longer time or the puzzle changed? I’m less certain there.
When the children eventually found the portal home, I think there was a person they found in that parallel world who could not return with them or who entered from a different portal and thus they would not be able to exit together but the main character then sees her somewhere?

When: 2004-2005


What reading level it is aimed at: children's chapter books

Genre: Likely sci-fi because of the portal and parallel world

Format: solid book, likely a paperback. I feel like the cover was white and I had my parents buy it for me but it’s no longer in my house if we ever had it. Probably about 200 pages, not terribly long but still a decently thick book (like about an inch?)

The puzzles in each chapter were assigned to us as homework each weekend, it was somewhat of a teaching tool in addition to being a novel if that helps

[Kris]

That's a great idea for a book. Note: The Cavern of Clues by David Glover is too recent and for younger kids, but I'm noting it in case other readers are interested in this theme.

[Lobstergirl, au gratin]

Sara, are you still looking for this or did you find it?

[James]

Looking for this as well please if anyone can find it. https://www.goodreads.com/topic/show/...

I think this post is the same book

[James]

If anyone else is looking for this I think it is Journey to the other side by Carl Sherrill.

[Rainbowheart]

Journey to the Other Side for James's suggestion.

[Lobstergirl, au gratin]

Lobstergirl wrote: "Sara, are you still looking for this or did you find it?"

No response, moving to Abandoned.