Figuring Out Celsius-Fahrenheit

When I first read your editorial, I thought Jack Smith was the author and was telling another one of his Senor Gomez stories. Then I realized this joker is serious.

You start out by saying “The usual method for converting from Fahrenheit to Celsius is cumbersome, difficult to remember and hard to do in your head.” Then you continue by saying, “If going from Fahrenheit to Celsius multiply by 5/9 (that’s easy to remember because the Celsius numbers are smaller . . . ) except from about 11.4C to -40C.

This is followed by “If you’re going from Celsius to Fahrenheit multiply by 9/5 (that’s easy to remember, for the same reason. Fahrenheit numbers are larger.)” Except of course from +11.4F to -40F.

You continue, “For example to convert 212F to Celsius, add 40 giving 252. Multiply by 5/9 (in your head) giving 140, subtract 40, leaving 100,” which is, of course, much simpler than just subtracting 32 from 212 to get 180, and 9 into 180 = 20 and 5x20 = 100.

Also, “If you want to convert 0C to Fahrenheit add 40, giving 40, etc., etc. All of which is so much simpler than 0x9/5 = 0 +32 = 32.

Now you know why your method is a secret.

To help you along, just remember that 20C is 68F, and for every 5C, up or down, the Fahrenheit temperature is 9 up or down respectively.

Example 25C is 77F, 30c is 86F.

H.C. JENSEN

San Gabriel