For some years I've been looking for a book that I enjoyed as a child in the 60s. I hope other baby boomers may be able to help?

The book was probably written in the 40s or 50s. It was about a small group of children who went back to the time of the ancient Romans (or Greeks), and explored, talked to people from that time, and did some sort of test or quiz. I get the feeling there was a professor with them, or perhaps the professor sent them there?

This book might have had a slightly educational viewpoint; I'm not sure. Because it was a library book, I didn't see it again.

I'd love to find this book again, thank you in advance!

Call/visit the reader's advisory desk at your public library. They have themed databases and print resources that might nail this down. I Googled but didn't come up with anything.