I would strongly urge you to consider throwing in a few of these from time to time.
Here is a puzzle (PowerPoint in resources section) you might want to use with your gifted and talented historians to encourage deep thinking about the nature of truth and transmission of ideas over time. They are introduced to a paradox which they have to explain as best they can. The puzzle is: If the Ancient Greeks knew that the world was a globe, why did so many people still believe that the earth was flat 1500 years later?
Having posed the puzzle, encourage students to come up with as many ideas as they can. Then ask them to whittle those down to the four they think most plausible. Then vote on the best answer. Slide 4 then gives them some options. Which is the best answer, the one they have already chosen or one of these? De-brief by going through each option and adding contextual information that will help deepen students’ understanding.
Puzzle Corner: Columbus and the idea of flat earth