Iron abacus, one to nine and one to one are those three numbers.

This question is a riddle, which needs to be understood to get the answer.

The topic mentioned "iron abacus, one goes to nine and enters one", which reminds people of the law of "one goes to nine and enters one" in abacus calculation.

In abacus calculation, "one to nine" means that when you dial "1", you actually dial "9" and when you dial "1", you actually dial "1".

Therefore, the phrase "one goes to nine and one enters" in the title actually requires us to express this action with numbers.

Through analysis, we can know that when you dial "9", you actually dial "1", so this number should be "9 1 1".

So the answer is: 9 1 1