Without a Character Palette, lean on Pages.
If you’re typing on a Mac, you have a variety of options on how to enter drawn or “true” fractions, ones that are typographically rendered to look like they appear in a recipe or in a book. I’ve covered that previously in “How to use macOS’s Character Viewer to type emoji and other symbols” and “How to insert fractions in Word and Pages.”
But what if you’re typing out an email or other text on your iPhone or iPad? Their operating systems lack something as simple as a Character palette. However, you can lean on the free Pages app that Apple offers to all iPhone and iPad owners. After installing, if you don’t have it, and launching Pages, follow these steps:
Now, as you type most single-digit fractions, Pages automatically reformats them.