On: Formatting floating point numbers

[tomxor]

That's a really succinct way of putting it. I would add a less catchy companion to highlight the affect of the formatter:

What is the relative error in 0.1? What is the relative error in 0.3? And what is the relative error in the sum? And whats the relative error in 0.4?

(i.e if they are the same it will be obscured by the formatter).