How to let a user know a number in the UI is rounded, and not an exact figure?

We’ve got a property in our user interface that can range from fractional (0.01 or so) to potentially millions. It’s usually over 1.

Before displaying it, we simply rounded it to the nearest digit and used K, M, B etc to show thousands, millions to keep it small and the level of precision sensible. So we’d display 2.3m instead of 2,324,499. 0.8 would just show 1.

The actual value isn’t too important in terms of precision (say, like a monetary value is) to the user – but it is important to the system to have a lot of precision as it determines the order of items. But the user isn’t going to mind if one value is 0.8 and another is 1.1.

However, we’ve added a search functionality, and someone brought up that if the user sees “23” in the UI, then do a search on this field for “=23”, it wouldn’t actually return the value they can see – as it’s actually 23.1149274829172892382 or whatever meaningless decimals.

How should we ‘telegraph’ to the user the number is rounded? Should we show the number in all it’s hideous precision on hover?