Answer provided by @jasonharper - see comments.

c.create_text() is creating the rotated text, and then t.write() is creating the unrotated text (containing the ID number of the rotated text you just created).

create_text() creates and draws the text item - there is no need to use any other code to display it.

The documentation for tkinter states that the function create_text(*args, **kw)

Draw text. Returns the item id.

So the unwanted numbers are the item id's of each of the rotated numbers.