- Try converting $25^@ "C"$ to $"K"$.
You should get $"298.15 K"$. That's typical room temperature.
- Try converting $39.2^@ "F"$ to $""^@ "C""$.
You should get $4^@ "C"$. That's the temperature at which water reaches its maximum of $"0.999975 g/mL"$. ;)