Some numerical data comes from some integrations with a upstream configured “offset”.
For example, “Tado” app let you configure an offset for ambient temperature, let’s say (for example) “-0.5°” on the thermostat reading, letting you a fine tuning of your reading - that comes to Home Assistant already corrected.
Sometimes you can’t correct the upstream data: the only solution is making a new template sensor with the needed offset.
Ok: the idea is letting users to put a numeric offset on the settings section of entity details box, as we do for icon, friendly name and so on. Of couse, this will have impact on the INSERT statement: offset must be an entity’s state correction on the db.