Numbers
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Check spelling in Numbers on iPad
Spelling errors are corrected as you type, unless you turned off the Auto-Correction setting for your iPad. If you turned off this setting, you can still flag spelling errors as you enter text in Numbers spreadsheets. You can also add terms to the dictionary so they’re not marked as misspellings.
Note: Spelling is checked according to the language of the keyboard you’re using, not the language of the spreadsheet.