Nine Tenths of a Cent

May 12, 2008 – 12:15 am

Gas stations in the USA have been selling gas at prices ending in 9/10ths of a cent for decades. Depending on who you ask, the practice dates back to the Great Depression or farther, and there are varying reasons given for it. The most often agreed-upon reason for it is that prices ending in 9 seem much cheaper than their counterparts that are a mere unit higher (like $19.99 versus $20) and thus cause an item to sell better. If you go back to when gas was 20 cents a gallon, selling for 19.9 cents instead of 19 cents, meant 4.5% higher profits. So if you could get the same psychological effect from 19 9/10th cents as you did from 19 cents, why not?

But when I see that 9/10ths tacked onto $3.69 a gallon, it's just sort of annoying. And on a gallon of gas I wonder how much gas that 9/10ths of a cent is buying?

This is 9/10ths of a cent worth of gasoline (or more precisely, olive oil standing in for gasoline for safety reasons). If you have gasoline that's selling for $3.69 and 9/10ths, you divide 128 ounces by 369.9 to get the number of ounces per penny, multiply that by 0.9 to get the number of ounces 9/10ths of a cent buys, then multiply that times 28.3 to get the value in milliliters. Why milliliters? When you get down that low, it's just easier to measure in milliliters.

9/10ths of one cent buys roughly 8.8 milliliters of gas. In non-metric terms, that's a smidge over 1 3/4 teaspoons. Put that in a one ounce shot glass and you get... well, not a very impressive amount of gasoline.

But, if you've been reading this site over the past month or so, you know that just figuring out 9/10ths of a cent worth of gasoline wouldn't be enough for me. I figured out a few others and took photos of those as well.

Our first candidate was popcorn. I made a run by Wal-Mart and picked up a 2 lb bag of generic popcorn for $1.34, but also noted that a 45 ounce jar of a premium brand — I won't divulge the name, but it rhymes with Norville Shmeckendocker — was going for $3.88. So here's 9/10ths of a cent worth of popcorn.

The kernels are all the generic stuff, so if Norville's kernels are bigger, you might have one or two fewer kernels, but that's the right weight of kernels at Norville's Wal-Mart Price.

In the same aisle, they had peanuts. Makes sense. So I decided to see how much those would calculate out to. The peanuts, at $2.28 per pound, looked like this:

That's basically 1 and 1/4 peanuts. I actually had to nibble that partial peanut down in little chipmunk-size bites to get to the 1.8 grams of peanuts 9/10ths of a cent buys.

Now, I like to do equivalents in food because I like to eat. But I also like to read and watch movies. Many, many years ago, when I was pursuing my degree in writing, I counted the words on random pages from random paperbacks and came up with an average word count of 335 words per page. Right now I'm reading Storm Front by Jim Butcher, the first novel in the Dresden Files series. It's not bad, costs $7.99, and runs 322 pages. At 335 words per page, 9/10ths of a cent worth of that book is 121 words, just slightly more than a third of a page.

Now the last movie I watched was The Astronaut Farmer. Caught it on cable and thought they used all the good scenes in the trailer. But if I'd been inclined to buy the DVD at Amazon, it's currently going for $13.49 and the Amazon listing states a running time of 104 minutes. Since it's hard to quantify the value of DVD extras, we'll just go with the running time, and that means 9/10ths of a cent buys me roughly 4.16 seconds of viewing pleasure.

So, what do you figure 9/10ths of a cent gets you in other areas? If you've got a Rough Equivalent for 9/10ths of a cent, post it in the comments below. And if you'd like the "shotglass of gasoline" image for use on your site or in print, you can download a high-res "shotglass of gasoline" image (right click on the link and select "save link as" or "save target as" to save the image to your computer). It is free for personal or commercial use so long as you credit me per the instructions embedded in the photo.