Something I Thought I'd Share

Like most Americans, I'm comfortable with measuring temperatures in Fahrenheit and must less so in Celsius (or Centigrade if you prefer). If someone tells me it's 22 F I can translate that into "cold", 85 F as "warm" and 110 F as "crap it's hot". If I encounter a Celsuis temperature I'm much less certain, what's 28 C? Now my cell phone is equipped with a unit converter, but I'm not going to whip that out every time I need to do a conversion (I'm nerdy, but not THAT nerdy). I know the formula, multiply the Celsius temperature by nine-fifths and add 32, but multiplying by nine-fifths in your head is hard.

Well, here I offer to my readers (both of them) an easy method to convert Celsius to Farenheit in your head. I don't pretend it's original, the math works so I can hardly be the discoverer of it, but I've never seen it anyplace else before. You can use it with precise numbers to get a precise conversion, or you can use close-enough numbers to get an idea of what kind of temperature we're talking about.

Here goes: Take your Celsius temperture, double it, subtract ten percent, and add 32. Each of these steps is easy to do in your head especially if you're doing a close-enough conversion.

Let's do an example, 28 C. Doubling 28 gives us 56. Ten percent of 56 is 5.6, subtract that from 56 and you get 50.4, add 32 and you get 82.4. That's a precise conversion, exactly what you'd get using the usual formula (in fact you ARE using the usual formula, just doing so in a way that's easy to do in your head). Suppose you don't need an exact number, your British friend just told you it's 28 C today. Call it 30 C (close enough), double it to 60, subtract 6 (ten percent of 60) to get 54, add 32 and you get 86 and bear in mind that you're a little high (because you rounded your original number up). So you know it was pretty warm, but not extremely hot.

I told you I'm a nerd.