How to correctly use "多" to say "more than"? I know a similar question has already been answered but I still have a lot of doubts.

To my understanding if a number is ≤9, you need to put "多" after the measure word (or after the name if it doesn't require a measure word), for example:


  两年多, 两个多小时, 两公斤多苹果, 四公里多


and if the number is >9, you need to put "多" before the measure word, for example:


  二十多年, 二十多个小时, 二十多公斤苹果, 四十多公里


When I told my friend "十一多年" he corrected me with "十一年多" saying that if the number ends with a number which is not 0 (like 1 or 2), you have to put "多" after the measure word, but if the number ends with a 0, you have to put "多" before the measure word (二十多年), except for 10, which requires "多" after the measure word (十年多).

I then asked for another example, this time with 天 instead of 年. In this case he said that both "十多天" and "十天多" are acceptable. The first one with the meaning of "from 10 to 20 days" and the second one with the meaning of "from 10 to 10.1/10.2/10.3/... days". 

I thought of an example that was written in that other question I linked at the beginning. If you add "多" at the end it refers to a number with decimals:


  "$50.5"(五十元多) or "$55"(五十多元)


In fact apparently this is also the case of "小时"


  十个小时多=from 10 to 11 (10.3 / 10.8...) or 十个多小时=from 10 to 20 hours


If I understood correctly this would add to the rules I wrote above a third one: if the "多" is at the end of a sentence the number will gain the meaning of a number with decimals. But why this is not the case of 年? Also, because of that I guess it's not correct to say, for example, "两多张床", because you can't really count bed with a number with a decimal. How do I say "more than two beds" then?

Are there specific rules depending on the measure word?
In my opinion, all the measure words, including 年，小时，and etc, work the same way. Let's take 年 for example.


多年 should be used only after numbers x10, like 10, 20, 30, .... For
example, 十多年：teens; 20多年：twenties; 30多年：thirties; ... ...
90多年：nineties(90-99); Thus, you can't say 9多年，11多年，...
年多 can be used after any positive integer numbers like,
1,2,3,...,100,...; 年多 connotes a bit more than, usually less than
1 year. For example, 4年 > 3年多 > 3年.


The same thing for other measure words. Both 五十元多 and 五十多元 are correct, but mean differently. "十个小时多=from 10 to 11 (10.3 / 10.8...) or 十多个小时=from 10 to 20 hours" is correct too. But expressions like 55多小时 and 55多元 are incorrect. 

As for the specific question "How do I say "more than two beds" then?", you can use 多于, 不止 or 比...多. More: 多; than: 比 or 于, so more than: 比...多, or 多于; For example, there are more than two beds in my home: 我家的床多于两张; 我家的床比两张多; 我家的床不止两张;