The median age in Gaza in 2014 was 18. According to researchers in the US, 50%-61% of buildings have been damaged or destroyed. If Israel didn't kill tens of thousands of children it would be a statistical miracle.
You're assuming the children are evenly distributed and buildings are attacked randomly and evenly. None of which is true.
Many buildings have been demolished with explosives or bulldozers while empty. Many buildings were damaged during combat with walls being breached to provide access.
In many cases buildings were attacked in areas that have been ordered to evacuate. (yes not all cases).
There's no doubt many children have been killed. We've all seen terrible photos of individual children dead. I don't think it's "tens of thousands" and I'm not sure we'll have accurate numbers. Other than that as you note there's a large number of children and so they've definitely and unfortunately impacted.
“Impacted” is definitely one word for it. Murdered another.
Words are important. And you're right those are different words. The word murdered has a specific meaning, e.g. "to kill (a person) unlawfully and unjustifiably with premeditated malice". The word impacted means: "strongly or directly affected by something especially in a negative way." The word "child" also has a definition. In this context it usually refers to people under the age of 18.
I'll turn the question back at you, what are you trying to get out of claiming "tens of thousands" or "murdered"?
I think the word murdered is IMO more appropriate to the children Hamas killed in Israel on Oct 7th and civilians it has killed in Israel over the years and less appropriate for the children killed in Gaza by IDF action during a war. That said my heart breaks for every single child, whoever they are, that lost their lives. It's not their fault. This war didn't need to happen. We should try our best to protect children, here and everywhere, and I do recognize that at some level you're trying to do so, thanks for that.
The article also questions your claim that the IDF was careful to protect civilians by eg destroying empty building. On the contrary, the IDF accepted extremely high civilian deaths to kill even one suspected minor militant.
I'm claiming many of the destroyed buildings have been empty. This really has nothing to do with the article. I'm addressing the parent's logic/argument. There have been many examples of buildings destroyed while empty, for example to make up the new boundary area Israel has created from the border. The attempt to calculate casualties via the number of destroyed buildings is a very poor methodology. Your statement and mine are not mutually exclusive- it's possible the IDF targeted buildings that had many civilians in them to get at one target. I don't know the demographics of those civilians. I don't know whether what happened in the early days of the war continued throughout the war. I would agree that early in the war Israel very likely accepted a larger number of civilian casualties to get at Hamas targets. I think the new thing potentially in this article is questioning the degree to which the targets were valid military targets.