How do I determine whether to use 次 (cì) or 遍 (biàn) in these sentences?

Question

The question comes from a problem from my Chinese book which asks to choose 次 and 遍 to fill in the blanks (photo of the original). I transcribe it below:

用“次”或“遍”填空。
(1) 杰希给马克打了两___电话，马克都没接。
(2) 今天的作业是：读五___课文，写十___生词。
(3) 今天马克一个人打了两___太极拳，下___他打算和阿里一起打。
(4) 我们一个学期考五___试，现在已经考了三___了。
(5) 上课的时候马克看了二十___表。

I feel like that most (all?) of them could be either 次 or 遍 without it being a problem. The only exception is in (3), where I would more naturally say 下次 (but Baidu suggests 下遍 is also okay).

From dict.cn:

• 次 (cì) = number (of times), and
• 遍 (biàn) = turn, a time.

So they really feel like synonyms.

Question: How do I determine whether to use 次 (cì) or 遍 (biàn) in these sentences?

(Note that this is not for assessment; I'm not officially enrolled in a Chinese class, but attend class regardless.)

Answer 1

From 《现代汉语词典》: (I'm omitting other unrelated descriptions of either word)

次: 用于反复出现或可能反复出现的事情

遍: 一个动作从开始到结束的整个过程称为一遍

Which is saying that 次 is used for things that (may) happen/appear/... repeatedly. And 遍 refers to the whole process (from the beginning to the end) of an action.

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The following explaination may be not that accurate:

次 seems to be saying that how many times you started to do something, but not quite care about how it persists.

In 2), the full action is required (from begin to end) so it is 遍。

In 3), the first blank, if he did twice consecutively, then it is 一次, but 两遍. Each 遍 is the full process from begin to end. If he did it once in the morning, but once in the afternoon, it is 两次. So maybe either is OK. For 下遍, it is not OK for me. But you can say 下一遍.

1), 4), 5) are all describing how many time a thing happened/happens/will happen, so they are all 次.

Answer 2

It may help to think of 遍 as "repetition" and 次 as "occurrence". The reading, writing (Sentence 2) and tai chi (sentence 3) all require repetitions of the same action, whereas the others are simply occurrences, not repetitions of the same thing.

Answer 3

Is it only me to think that, if in real scenario, either is ok.

用“次”或“遍”填空。

(1) 杰希给马克打了两___电话，马克都没接。

次, but in practical, Chinese will use 遍

(2) 今天的作业是：读五___课文，写十___生词。

遍, I don't why, we just use it.

(3) 今天马克一个人打了两___太极拳，下___他打算和阿里一起打。

次 grammatically, but we use 遍

(4) 我们一个学期考五___试，现在已经考了三___了。

次

(5) 上课的时候马克看了二十___表。

次 grammatically, but we use 遍

There is not too much grammar cause, just convention and behaviour.

Answer 4

(1) 杰希给马克打了两_次_电话，马克都没接。

(2) 今天的作业是：读五_遍_课文，写十_遍_生词。

(3) 今天马克一个人打了两_次_太极拳，下_次_他打算和阿里一起打。

(4) 我们一个学期考五_次_试，现在已经考了三_次_了。

(5) 上课的时候马克看了二十_遍_表。

遍 implies the completion of an action from beginning to end, such as reading a book or watching a film from beginning to end.