Yes. Most nouns don't differentiate between singular and plural, but たち does make this plural. Similarly, 人たち is also used for "people," with the たち making it plural.
You won't see it very often except for with pronouns, like for example, わたしたち (us/we) or あなたたち (you all/you guys). ら can also be used in place of たち in the case of plural pronouns.
Thank you! One final question : Is there a difference between たち and ら? Is one more formal or polite than the other?
I believe たち is more formal than ら, but not necessarily much more polite.
It's a little different from plural actually. It indicates the collection to which the noun belongs. It's closer to meaning 'children in general' than it is to 'some number of children greater than one'.
This being the case, I would have thought "the children" should be okay?
iirc it also makes it specific (ie, that particular group of children, not children in general)
The word can be written as "子供達," but 達 is not very common. Also, some people urge that you must leave 供 as hiragana (子ども) because 供 has no actual meaning in this word, and this kanji originally means religious offering, which may cause misunderstanding.
Well theres no real Japanese word for "the". Now in a language like Spanish or French theres a different emphasis on direct articles.
That ia exactly why I would think "the children" is an acceptable answer. If 子供たち can be translated as "children" or "the children" because Japanese lacks a definite article, why would the app not accept both?