The Special characters browser
Insert → Special characters opens a searchable grid of the whole Unicode range. Search “euro”, “arrow”, “check” — or draw the symbol with your mouse in the right-hand box and Docs guesses it. Click inserts at the cursor. Recent picks sit in the first row next time.
Need a right now without the browser? Copy it here — Docs accepts pasted Unicode flawlessly.
Substitutions: Docs' AutoCorrect
Tools → Preferences → Substitutions: add rows like “(e)” → é or “-->” → →. (c)→© and smart quotes ship enabled. Unlike Word there are no custom shortcut keys, so heavy symbol users should lean on substitutions plus this site's picker.
Why Alt codes fail in Docs
Alt codes are a Windows OS feature delivered to native text fields; Docs runs in a browser canvas that never receives them. Same for most web apps. Use the browser, substitutions, or system-level input (Character Map, Character Viewer, phone long-press) and paste in.
Equations for maths
Insert → Equation opens a LaTeX-flavoured editor: \alpha, \pm, \times, \neq all resolve on Enter. For inline symbols in body text (a ± in a sentence), the browser or copy-paste is faster.