How to type alt codes with no numpad?

In some Windows programs you can enter the Unicode value then press AltX. e.g. typing 2234AltX will give a ∴ symbol.

This works in Microsoft Office (Word) and Libre Office (Write, Impress, Drawing). I assume it will work in Open Office as well, but I don't have that to hand. It's interesting that Libre Office supports this in more apps than Microsoft Office does.

On Windows 10 you can enter emojis, in any app, using ⊞ Win..

find the character you want on a website, copy, paste

you can search for something like "alt keypad characters" and that will give you lots of options

Observation

I could type them by by holding the Alt key and clicking the OSK numpad (on-screen keyboard), but it was very cumbersome. I also noticed while using the bluetooth numpad the OSK numlock key would flash, leading me to believe that the device was programmed to automatically toggle numlock with each button press, as it does not have a dedicated numlock button.

Solution

Use Sticky Keys to virtually hold the alt key while the bluetooth numpad is used:

    Settings app > Ease of Access > Interaction - Keyboard
        ON "Use Sticky Keys"
        CK "Allow shortcut key to start Sticky Keys"
        CK "Show the Sticky Keys icon on the taskbar"
        CK "Lock the modifier key when pressed twice in a row"

If you wish to also use hex codes (ex U+2220):

    regedit > ComputerHKEY_CURRENT_USERControl PanelInput Method
        New string value
        EnableHexNumpad = 1

Notes

To en/disable, tap shift 5 times.
To use alt codes, double-tap alt, punch the code on the bluetooth numpad, and single-tap alt.
To use hex codes, same as above, but tap "+" before the code.

The SK taskbar icon shows when the alt key is being virtually held.
You can also set it to beep if desired.