Open ended problem: Boarding passengers onto planes

Via Riley Lark’s blog

This might be an interesting conversation starter for a class: what’s the best way to board an airplane?

The students will probably have lots of ideas to discuss, and best of all, every single one of them will be better than what the airlines actually do.

At most vs at least

This next example comes from Sue VanHattum.

Me: Clean up your drips!
R: There aren’t any.
Me: I see at least one.
R: You see at most one.

When do children start using logical reasoning? Can we find other examples of children thinking like this?