If you're going to take it that far you have to add "at standard pressure".
Also, I was under the impression that coolant does not boil at that high a temperature at standard pressure. The point of the sealed coolant system is to increase the pressure and hence the boiling point, but if it boiled at that temperature by default that would be unnecessary since no engine runs that hot.
Those are exactly the same, it's not an approximation. (212 - 32) / 9 * 5 = 100 exactly. Water boils at exactly 212 Fahrenheit under 1 atm pressure.
~95°C here (Denver, CO). Flatlanders. ;-)
> Water boil at exactly 100 degrees Celsius
Few people live exactly under 1 atm for any length of time.