~snip~
You did not say anything 1)why gambling is bad and you think it is better not to show them it 2)why kid will become gambling addicted if he sees that adult gamble?
About my example with swimming and chewing gum. It was all done to make competition more interesting, to increase desire to win. Why do you think it is bad to do that? In this case, a bet = a reward.
Gambling is bad if they lose control. If we don't show it to them, that's fine too, right? They also don't have to gamble their whole lives, even if it's just once. Gambling is a choice, and if they don't see that choice, they don't need to gamble. I have many friends who have never gambled once in their lives, and their lives are fine. They never even saw adults gambling when they were children, and they did not gamble when they were children. Their life is fine.
Do you want to take the risk of gambling in front of your children, and later, you will see your children also gambling like you? I don't see that happening to my kids.
Now, if you notice some children gamble when they often see adults gambling, they gamble with their friends. This will later become a habit in their relationships and will be carried over until they grow up. If they think gambling is normal, who will be responsible if they become addicted to gambling? It must be his parents or the people around him. If they didn't have to see gambling, no one would be bothered by having to help him cure his gambling addiction.
When pleasure becomes a desire to bet because of the reward factor, they will become even more addicted. If it can benefit them, go ahead. But remember, they will feel challenged to prove they can always win. But if they lose, they will fall into an abyss from which even they will find it difficult to rise.