The Lancet report puts about 42.8 percent of the recoded killed being nineteen or under. Assuming that raitio has remained consistent, and using the twenty one thousand, five hundred and seven deaths recorded as of Dec 29th, that puts the number of dead kids at nine thousand two hundred and five.
While it is more difficult to actually figure out how many Hamas Israel have actually gotten, given that a lot of the Israeli fire has been launched at buildings where Hamas broke in, lobed a RPG from a shoulder fired launcher, then drove off within a minute, or have been against refugee camps and other purely civilian targets, it’s unlikely that many actual terrorists more important than the now easily recureted cannon fodder have been successfully killed. Especially given that many of the ones involved in the all or nothing attack on Oct 7 never actually made it back to Gaza.
Moreover, given that Israel has been more than happy to share names when it actually has them, and generally there haven’t been that many, putting a vague estimate at about a hundred or so isn’t that unreasonable.
Even the best case Israeli numbers put it at less than one terrorist per kid, given their reluctance to back any of that up the amount of evidence they have since walked back, and how terrorist groups are organized in the first place, it is very unreasonable to use said estimate.