The "spell" key will spell out the current value to the History Detail.
Pressing the (i) key (i in a circle) will display the History Detail.
This is useful to generate the accurate spelling for contracts and other documents where the spell out of values is required.
Spell Out of : 98771.99
ninety-eight thousand seven hundred seventy-one point nine nine
The spelling will be according to your language and local setting.
Spell Out of : 98771.99
quatre-vingt-dix-huit mille sept cent soixante-et-onze virgule neuf neuf
The value will be rounded to the current setting for the spell out. The value in the display is not changed.
I found that having English second in the list of "PREFERRED LANGUAGE ORDER" in "Language & Region" settings will cause the spell out to be in English.
See documentation on History to view and share the spell out to a document.