Aelfwine is correct that Tolkien did not have a calculator and I expect that he did the calculations by hand, long division, etc. https://en.wikipedia.org/wiki/Long_division

He may have also used a slide rule (https://en.wikipedia.org/wiki/Slide_rule) or Log Tables (https://en.wikipedia.org/wiki/Mathematical_table).

Finally, I doubt that he would have owned one of these, but the University would have had mechanical calculators (https://en.wikipedia.org/wiki/Mechanical_calculator) so he possibly could have used one, but very unlikely as they were not simple to use.

I have put an "Addenda and Corrigenda" for The Nature of Middle-earth on the web here. Please spread the word, and please send me any additional corrections you notice. Thanks!

Thank you Carl, excellent work. I will use these to update my eBook edition and my working copy of the hardcover.

Thank you Aelfwine!

(Small note - there is no link yet to the pdf file from the errata page itself, https://elvish.org/errata/ )

I'm continuing to work on my paragraph referencing scheme (less important here because of only a single pagination but still useful for certain work) and I'll map the errata locations to that once I'm done.

Bookdepository have a listing for a US paperback on the 6th September 2022.

https://www.bookdepository.com/The-Nat ... F-Hostetter/9780063269606

Format Paperback | 464 pages
Dimensions 139.7 x 209.55mm
Publication date 06 Sep 2022
Publisher HarperCollins
Imprint William Morrow & Co
Language English
ISBN10 0063269600
ISBN13 9780063269606

Blackwell's (affiliate)

The Nature of Middle-Earth

Tolkien, J. R. R./ Hostetter, Carl F.

9780063269606

(Unknown)

$24.16

Availability: Unknown

Check at Blackwell's

Amazon.com (affiliate)

The Nature of MIddle-Earth

Tolkien, J.R.R.

9780063269606

(Paperback)

$17.99

Availability: Preorderable

Check at Amazon.com

Have added to the store, under "forthcoming"