The insertion point is simply the blinking cursor. It's what you see if you just click in text (making sure not to select/highlight anything).

Your example files include pasted pictures, which doesn't tell me anything. But if you can select one number at a time, most likely they are typed in.

Have you tried Find and Replace? Just in case, you can work with a copy of the document, to avoid unexpected results in your original file.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional