Does A が B となる mean “A becomes B”?

Question

The sentence in question: 店員さんに話を聞くと、「１０年ほど前から海外のだっこひもが人気となり需要が高まった。

For full context: https://www3.nhk.or.jp/news/web_tokushu/2018_0521.html?utm_int=news_contents_tokushu_004

My attempt at tranlstion: When we asked the shopowner the story: "Since before about 10 years, the foreign "dakko" cords have become popular and the demand has risen."

Ive encountered the と particle in various uses about which my textbook has never told me anything, and many of them meant something like "make A to B". So this question is just for confirmation that I guessed correctly here :D

Answer 1

You're right.

AがBとなる means "A becomes B". ～が～となる sounds less colloquial and a bit more formal than ～が～になる.

海外のだっこひもが人気となる
Baby slings/carriers from overseas become popular
(≂ 海外の抱っこひもが人気になる)

_{You can think of 「AをBとする」 as its transitive counterpart: Intransitive 「AがBに/となる」(A becomes B) -- Transitive「AをBに/とする」(make A B; think of A as B)}

Answer 2

Apparently 〜になる and 〜となる are pretty much equivalent (become ~), but there is a small difference in nuance. If I understood this Oshiete! Goo answer correctly, に is used for natural, obvious results and と when the development is sudden or somewhat unexpected. This example was given:

「すったもんだの末、結局彼が村長となった。」

After an awful fuss, he became the village chief in the end.

「すんなりと彼が村長になった」

He became village chief without much difficulty.