Hi, in level 3 of the Wanikani system I learned the word “~台” which is translated as “big machine” or just “machine”. I do not understand what that is supposed to mean. From the examples and explanation I guess that I can replace the ~ by any number to express how many machines there are.
On the other hand, there are explicit vocabulary words like “five machines” on the same level. Is there a difference between the two? (i.e. why can’t I just replace the ~ by 五?)