How to type a number in superscript or subscript

About superscript or subscript numbers

How do you type a number in the upper or lower index if the text editor has no idea what an index is? For example, in a regular Notepad (and, by the way, in Telegram).

This is where Unicode comes in. It has ready-made symbols for numbers in the upper and lower indices, as well as pluses and minuses:

• Upper: ¹²³⁴⁵⁶⁷⁸⁹⁰ ⁺⁻
• Lower: ₁₂₃₄₅₆₇₈₉₀ ₊₋

Example of upper and lower indices typed with special characters:

The half-life of ²³⁵U (Uranium-235) is 7.13·10⁸ years. Uranium forms oxides UO₂, UO₃, U₂O₇.

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Notes:

• If we are talking about something square or cubic, you can skip the bother and just write it in abbreviated form: 100 sq km, 10 cu m. These abbreviations are easy to understand.
• There is no need to mix differently typed indices. If you’ve already started typing indices, for example, as separate characters, do so throughout the whole text you’re working on.
• A complicated case is when you need to enter both the upper and lower indices at the same time, for example, UO₄²⁻ (here the indices should be above each other). Standard methods will not do this, special efforts are required.