While watching TV with my kid, I've watched various advertisements of gambling nature (let's say for example, Rummy123, RummyCircle, A23 Rummy, etc.)
These are all specifically Indian ads, but I'm sure you may have seen various gambling advertisements, some banners at boundaries when cricket is ongoing, even in any other sport. How would a kid ignore those things, they might just come and ask you about what is it. Till when can we lie to them? Don't you think that the frequency of such ads must be less in order to let the kids not get trapped into gambling and don't do it at such a small age?
I think for some TV channels they usually advice parental guardians for some programs that are rated as such so for such program we could ask the children not to watch such channels, for TV where there's parental controls on them they would permit such to be shown on the tv as the parental control will cause a restriction on the channel.
I'm actually advising the usage of parental controls on our TV if we don't want our kids exposed to certain things as this because when they are exposed to it they would ask questions as it's in their nature to be curious and want to have an idea into almost everything they see around so the only way out will have to be to reduce their exposure to such things, for kids channels the don't permit such ads because they know the kids aren't their target audience and so such shouldn't be displayed on their channels but in a case where they happen to see it probably when you watching TV with them you could tell them to ignore it as it doesn't concern them.