The Torah tells us that if an ox kills a person, the owner of that ox is put to death, but at the hands of Shamayim, at the hands of heaven. We don't actually kill him in a beit din (court) on this earth, but the owner has the ability to save himself by paying a kofer, a ransom. He pays that to the heirs of the person who was killed. It becomes part of his estate.
Mishnah tells us more about that. Mishnah says that if an ox gored a person and that person died, then if the ox was mu'ad, it already killed three people, the owner pays a kofer. But if it was a tam animal, didn't kill three people before, then the owner does not have to pay that. Kofer doesn't have to pay that. But both of these oxen, the tam ox and the mu'ad ox, are put to death. They're stoned, as the Torah tells us, because they killed a person.
The same applies if the victim here was a boy or a girl, not an adult but a young child. If they were killed as well, then the ox is killed too. A person would think, “Oh, maybe it's only when it's an adult.” But the Pesukim (verses) spell out: If a boy or a girl was also gored, the ox is killed as well in those situations. The Pesukim also say that if the person killed was an Eved, if a slave or a maidservant was killed, 30 shekalim (shekels) are paid to the master, and the ox is killed as well. The Pesukim also say that if a boy or a girl was also gored, the ox is killed. We'll talk about that halacha (law) now.
If an ox killed a Kena'ani (Canaanite) slave or a female maidservant, then the ox is also put to death, and the owner has to pay a fine of 30 shekalim to the master. It doesn't matter what the slave was worth: whether it was worth 100 maneh (unit of currency), whether it was worth ... a single dinar (coin), it doesn't matter. It's worth 30 shekalim, the amount paid automatically, as the Torah tells us.