You may call it a contest where those who predict correctly wins the prizes. The difference between this and gambling is that here you are just participating in prediction without investing your own money while in gambling you would invest your own money in order to participate in prediction.
Anyways I do agree that most people will consider these two scenarios as same and will treat both of them as gambling.
people don't understand the context here, can gambling without money be called gambling, it doesn't mean that participating in a contest can be called gambling even though playing gambling or competition because without using money it's hard to say it's gambling because there's nothing at stake, even in my opinion it's gambling using fake money or demo game can also be called gambling but unfortunately it is only fake money as a demo.
We cannot consider any betting without money as gambling. There are some situations where money is not exchanged but is treated as a bet. I have some friends who sometimes bet with some others friends where they don't prioritize money. But if they lose the bet they are obliged to give treats. Can i consider such bets as gambling? Not, Because there is no direct relation to money. Moreover, no one has any regrets even if they lose.
We can not consider gambling when there's no money involved but if they will use things as a bet then it will be called gambling for me. Because once you are guaranteeing anything then that must be called gambling. Anyways nowadays gambling is everywhere means whenever you go there's a gambler playing their favorite game and bet some money hoping that in the end of the day they will gain more money.