Myself and my partner bought 2 baby oscars, they are not really tiny we are not that stupid but they are too big for him to eat! He is however trying to eat them and has caused one of them significant damage. If we section off the tank for a while with some kind off thick glass or plastic will he get used to the presence as they grow bigger or will he kill them as soon as we remove the partition. Answers asap would be brilliant we dont want our new babies to die!

I dont think anyone could answer that for you. oscars are very different from fish to fish. i have 3" clowns with full grown oscars that have never touched them. it will depend a lot on your fish temperament. once your small fish reach a few months old they should have a better chance. dont use feeders,prawns or meats. stick to pellets and worms for food as this makes them less aggressive. they may just get use to each other as they see each other more each day. you could also move items around in the tank to take big fish mind off little fish.

I do have a silver dollar in the tank too so im hoping that he will get used to them, thanks for the advice

How big is your tank? You've heard the expression, 2's company 3's a crowd, well, this can often applied to Oscars, especially in the tank isn't very big. If two of them pair off, the third Oscar could be in for very rough time as Oscars can be aggressive during breeding periods.

Oscars have got eyes bigger than their belly and what ever they can fit in their mouth, they will try and eat. If the larger Oscar keeps grabbing hold of them, you're going to have to remove the fish from the tank. Sectioning the tank is an option but only if it is a large tank. If your tank is four or 5 feet in length, you can't expect a large Oscar to live in that amount of space for the time it will take the other Oscars to reach a safe size.

It's a bit of a difficult situation and my advice probably won't be what you want to hear. However, your large Oscar obviously it can go after any small fish. That means you cannot put those Oscars in there with it at the moment. I would seriously consider re-homing the small Oscars unless you have a large tank that you can divide. But please consider what I mentioned about the amount of Oscars you keep together. Even though Oscars aren't vicious killers like some people like to make out, they can be aggressive towards each other. This can often result in one of the Oscars being ostracised which isn't really fair

as was previously mentined no one can predict how 2 fish will interact with each other. i agree with ofl and if your tank is not large enough to partion into two (6 feet long or more) you hsould either rehome the small o's or put them into a grow out tank until they are big enough not to be considered food.
even them you could still run into aggro problems.

I should also point out that silver dollars are shoaling fish and therefore should be kept in groups to reduce stress.

i would recomend rehome the new comer or rehome the big oscar.
new comer is considered intruder. even if not small enough to
be eaten, teritorial supremacy is an issue, to the extent of
killing the new comer. partition will be temporary but no assurance
of acceptance.