In this dialogue, why does 一米八几 mean "more than 180cm tall"? My HSK 2 textbook contains the following dialogue and translation:


  他多高
  How tall is he?
  一米八几
  He is more than 180 centimeters tall.


The second sentence is not explained in the book and I am struggling to understand it:


What is the purpose of 几 in this sentence?
Google Translate tells me it means "One meter eight" and a reverse translate gives me 一米八. Why is the book saying 1m 80cm instead of 1m 8cm?
Why does the book's translation include the word "more than"? Which character is providing the meaning of "more than" in this sentence? HanziCraft does not list this as one of the meanings of 几, for example.
一米八几 means 1.8 x meters, where x is usually between 1 and 9. So the person's height is between 1.81 meters and 1.89 meters.

Therefore for your first question, 几 stands for some number that the speaker can not provide an exact value.

For your second question, the translation by google is not quite correct.

And for your last question, the meaning a few is what is being used in this sentence.