Ripped off because we don’t do well at math

I’m in the process of reading Stopped Getting Ripped off: Why Consumers Get Screwed, and How You Can Always Get a Fair Deal, by Bob Sullivan (2009).  He starts off by asking you to pretend that you are in a restaurant and you are presented with a menu that he illustrates on page 5 of his book. You are asked to assume that you ordered the onion soup (the price is clearly listed on the menu as $.60) and the “Lancaster Special Sandwich” (the price is clearly listed on the menu for $1.95).

The question he asks is this: “How much should you leave for a 10% tip?

I’ll wait for a bit while you do your calculation in your head. No calculators, please.

What did you come up with?

[more . . . ]

The answer is 25.5 cents, so either 25 cents or 26 cents would be an acceptable answer.

What Sullivan next states is shocking:

If you answer this question correctly, consider yourself part of an elite group, because when the US Department of education asked US adults to answer it as part of a nationwide study, only 42% answered correctly. Less than half of American adults were able to pick two numbers from the list, add them, then perform the most basic of all percentage calculations–simply moving the decimal point one column to the left to calculate 10%.

Innumeracy is literally killing us. Try to think of a major issue facing our country that does not require a basic proficiency in mathematics that most of us don’t seem to have. Think of the environment, energy, national budget, climate, health care, evolution being taught in public schools, space exploration, public health issues (e.g., the importance of vaccinations), the true cost of the “war on drugs,” reform of financial institutions or taxation policy.   Since most Americans cannot understand how to calculate a 10% tip, there is little chance that they could meaningfully participate regarding most of the big issues facing our country.  These are truly painful words to write.

Just think of the many math-related claims that got math-ignorant voters excited during the last presidential election, including Sarah Palin’s claim that American could live long and prosperously on Alaskan oil (when straight-forward calculations based on known reserves showed that there is only enough Alaskan oil to supply America’s current rate of use for six months).   Imagine how different things would be if most Americans could actually calculate the minimal chance that they would be affected by an act of terrorism, and if they were able to compare that risk to the immense numbers of lives that could be saved by much more modest expenditures. But it’s not even clear whether most Americans can benefit from further training regarding statistics.  It’s certainly true that many health care professionals don’t adequately understand basic problems involving risk.  The reasons so many of us are innumerate are not easily addressed.  We desperately need proficient math skills to tamp down our fears.

I know it has been tried (and abused) before, but a sinister thought enters my mind.   The information presented by Sullivan makes me wonder whether we should make voters take and pass a rudimentary math test before allowing them to vote.  How indignant could a rejected voter be if he/she can’t figure out a ten percent tip?  Understanding the many math-based claims asserted by candidates is sometimes the only way to see past their slick acting abilities.

I’m not seriously suggesting a poll quiz, though I’m sure that my frustration is showing through.  What we really need to do is provide better math education all the way through school.  It appears that we are paying dearly for the many grade schools that fail at math education, individually and as a country.

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Erich Vieth

Erich Vieth is an attorney focusing on civil rights (including First Amendment), consumer law litigation and appellate practice. At this website often writes about censorship, corporate news media corruption and cognitive science. He is also a working musician, artist and a writer, having founded Dangerous Intersection in 2006. Erich lives in St. Louis, Missouri with his two daughters.

This Post Has 6 Comments

  1. Avatar of Zedge
    Zedge

    I was reading somewhere that HP charges people up to $8,000 a gallon for printer ink! Did you know that ingredients in Xanax cost about $.03 to make 100 pills? They charge $136.79 that's is well over a half million percent markup! That should just be Illegal! Math, ya gotta love it!

  2. Avatar of Mark
    Mark

    I literally can't imagine what it would take to goad people into taking steps to fight their own ignorance. It's an increasingly complex world, but ignorance is more popular than ever. People seem to love it. What do you do about that?

  3. Avatar of Zoevinly
    Zoevinly

    I'm incredulous. I thought for sure there would be more math to perform after the jump! This is the stuff that should scare us silly, but what can the "elite" consumer do about math education in the states?

    Speaking of ignorant consuming, I hear the stories of everyday folks who went to buy a car, handed dealers the keys to their trade-ins and put down several-thousand dollar down payments. They drove away the new car with a promise from the dealer to find the best available financing for their car loan only to discover, after WEEKS or even MONTHS, that the original vehicle pricing and financing terms had COMPLETELY CHANGED.

    These consumers agreed to buy the car, even though every term they'd bargained for had been re-written. Now, tell me: Is this a crisis of math incompetence, or the failure of our education system to teach people how to assert themselves?

    Maybe I'm just begging the question. If you can't calculate a 10% tip, are you less likely to disagree with your car dealer when he tells you that the price of your new car is $7,000 more than you originally agreed upon, at double the interest rate?

  4. Avatar of Edgar Montrose
    Edgar Montrose

    This may have been mentioned previously in another context, but search for the "Dunning and Kruger Effect". Unfortunately, the less competent a person is, the less likely they are to be aware of it, and the less likely they are to accept it once proven to them.

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