わりに vs にしては Which one is the right one in my sentence?

Question

Today I came across the topic of にしては and わりに on my grammar n2 book. I understood that they both mean “for” but にしては should be used with only specific words such as 2月, 50歳, etc… while u should use わりに with more general words like 値段 or 年齢. I’ve done my exercises and I got almost all of them right but I cannot understand this one:

ここは幼稚園(……)、賑やかな子どもの声が聞こえない。

a. のわりに b. にしては c. だけあって

I chose A but in the solutions, it says B but I cannot really understand why. Could anybody help me please?

ヽ(￣д￣;)ノ=3=3=3

Answer 1

The core meaning of 割【わり】 is "fraction; rate; proportion", so わりに is usually used when referring to a continuous or ordinal scale that can be described using big, high, small, low, etc. You can think of 年齢のわりに as "proportionally to one's age", 学歴のわりに as "proportionally to one's educational background", and so on. However, in your sentence, 幼稚園 is used simply to refer to a type of institution, so it's unnatural to say 幼稚園のわりに ("proportionally to kindergarten"?).

Note that you can use both のわりに and にしては for 50歳, 2月, etc. 50歳のわりに若い and 50歳にしては若い are interchangeable. 中学生のわりに賢い is also okay because there is an "(educational) scale" in the speaker's mind, but something like 日本人のわりに英語がうまい starts to sound a little questionable, and 日本人のわりにピザが好きだ sounds awkward to me.

Answer 2

I'm going to take a crack at this one, and I'm sure a native speaker can offer more context and correct me as necessary.

にしては has a stronger contrastive sense than 割に, and 割に has a more general comparative sense.

In this case, you want to express strong contrast: You would expect a kindergarten to have lively children's voices, and yet at this specific kindergarten, there are none.

割に is used in a situation where you're talking about a mildly or relatively unexpected state. Like, "For a cold day, not so many people are wearing coats":

今日は寒い割には、コートを着ている人が少ない。

This is a mildly unexpected state, and it also has a sense of "proportion" suggested by the word 割. Give the temperature, I would expect a larger proportion of people to be wearing coats than I actually see.

Now, if you were going to say, "This is Antarctica, and yet no one is wearing a coat," now you're in にしては territory. That's an expectation about a specific place that is being strongly contradicted.