An easy approximate way to convert Celsius to Fahrenheit: double C and add 25. Example: 30 degrees Celsius X 2= 60, add 25= 85F.
The accurate conversion formula is 9/5 X C+32= F So: 30 X 9/5=54, plus 32= 86F exactly.
As C climbs higher than 30, or drops below 30, the approximation formula is less accurate but close enough for government work, as they say.