Enter a number either in the form 12,345 or as English ("one hundred
and eighty"), and it will be converted into Japanese kanji numerals.
Don't use daiji (bank-style numbers)
Use daiji for 1, 2, 3, 5, 100, and 1,000
Use daiji for 1-9, 100, and 1,000
See also this list of numbers from one to a hundred, and how to write large numbers in Japanese.