Superboy gets his first cover story in More Fun 105 (Sept/Oct 1945), and the cover even reflects the story, as Superboy plays marbles against other kids.
There is a bit more to this story, pencilled by Joe Shuster. Clark overhears a local plastics firm wishing they could contact Superboy, and quickly changes clothes and goes to see them. They explain that they lost a secret formula, which is now residing inside a child’s marble. This is the fishiest story imaginable, but Superboy believes it without question.
Superboy sky-writes an announcement about the big marbles championship, but of course wins all the kids marbles himself. He claims at one point to be doing his amazing shots without using his x-ray vision, but is he really? It’s critical to the plot that he acquire all the marbles. No reason to think he wouldn’t cheat in order to do so.
In the long run he plays fair, returning as Clark Kent in order to lose all the marbles back to the kids, once the people at the plastics factory find their “missing formula.” At least Clark takes the reward money and uses it to build a playground for the scammed youngsters.
And once again, with no glasses, how believable is it that the kids do not recognize that Clark is Superboy?