Ten/ta/to/ci/te can be translated both as this/these and that/those in most situations. When there is a contrast (you want to distinguish between this thing and that thing) or large distance (that thing is far away), you can use tamten/tamta/tamto/tamci/tamte, which means that/those only.
I understand your logic, but with this particular example it is in fact not masculine-personal. The singular word "dziecko" (child) doesn't show gender, it's neuter. So we do not know anything about the children's gender. While they may even be all boys, "dzieci" will be grammatically not masculine-personal anyway.
I heard of the terms singuar and plural verb in a polish grammar book. Now i can see what they meant is jedza would be a plural because it used with the plural children.
The singular forms in nominative and accusative are explained by Duolingo (demonstrative pronouns), but not the singular instrumental and the plural forms. So te and ci are not being clarified yet. Can anyone help me with these? Better yet, can anyone help me complete these forms?
It seems this is a shared sentence with the English for Polish speakers course, where they use "ten", "te", etc. to explain the meaning of "the". "The children" and "These children" mean more or less the same thing, we always accept "the" in such sentences. But it shouldn't be the main translation.
I will remove this sentence and create one that is not shared with the other course.