That’s how I convert between Celsius and Fahrenheit, if I have to do it in my head: Add 40, multiply by 9/5 or 5/9 depending on what direction, subtract 40. Eas

That’s how I convert between Celsius and Fahrenheit, if I have to do it in my head: Add 40, multiply by 9/5 or 5/9 depending on what direction, subtract 40. Easily remembered!