Find placement or order of word in UITextView

I want to find the position of a word in a textview, so that if I have a textview with 300 words, and the user taps on word number 100, a UILabel reads, "100" and so on.

This seems like a helpful place to start to select a word in a textview. And I can go here to get the word count of the textView. But beyond that I'm not sure.

Any ideas?