A number is a single term so there cannot be a 50th term for a number.
I'm unable to provide the 50th word in the dictionary as it can vary depending on the type of dictionary being used (e.g., Oxford, Merriam-Webster). If you have a specific dictionary in mind, I recommend checking the index or using the search function to locate the 50th word.
Answer: its a 0.
50th
100
50th
If n is the first of these numbers then the 50th is n + 98.
Fiftieth
The ordinal number 50th is spelled fiftieth.
I'm unable to provide page numbers or search specific editions. You may want to use the book's index or search feature to locate the word "acquit" in the 50th anniversary edition of "To Kill a Mockingbird."
100