About Me

My photo
I'm a life-long New Englander, father of 4 challenging kids (I know: I'm supposed to say "wonderful", but while that'd be true, technically speaking, it'd also be misleading), and fortunate husband to my favorite wife of more than 20 years. I've got over 20 years experience breaking things as a test engineer, quality engineer, reliability engineer, and most recently (and most enjoyably) a Product Safety / EMC Compliance Engineer. In the photo, I'm on the left.

Thursday, December 6, 2012

Dividing by way of Multiplying

It may be that I'm an engineer, or it may be that the reason that I'm an engineer is the same reason that it bothers me, but I really get a wrinkle in my panties when I hear a lecturer, or see in an ad or on TV (or hear on the radio...) people using math incorrectly.

I'm not talking about when people make an error, and assert that 2+2=p.

I'm talking about when they just don't seem to understand what they're actually saying, but they're talking with great authority and confidence.

I know: what?

As examples:

"Eight times lower"...shouldn't that be "one eighth"? How can something be "Eight times less" than anything? This basic error I see frequently, and I'm sure that my beautiful wife is tired of me pointing it out when it crops out, but it bugs me.

There was an ad for a speed reading system on TV that asserted that you could experience a 1,000% increase in your reading speed. Wouldn't it be great to read everything 10 times faster?

Well, an increase of 10X isn't the same as a 1,000% increase.

Start: 100
A 100% increase brings you to 200, which is 2X.
A 200% increase brings you to 300, which is 3X
It's actually a 900% increase that will bring you to 10X

Here's one that had me wondering:

"We multiplied our efficiency by 50%"

Well, that just sucks. If you started at an efficiency of 100, and you multiply that by 50%, you're now at 50.

This means you got less efficient. You are now half as efficient as you used to be. I wouldn't crow about that.

This is on the coat tails of "Divided by half". When you divide by half, you end up with twice as much, but the advertisements are usually suggesting that you get half of what you started with. I'd hate to divide my electric bill by half...I'd end up paying twice as much!

I recall back in the year 2,000. The Millennium.

Ah, no...that wasn't the Millennium. Of course, those of us who pointed that out were ridiculed endlessly (actually, that's not accurate: the ridicule did end, eventually), and I'm really not sure why. The transition from December 31 2000 to January 1 2001 would have been the Millennium. The mass media and the mainstream didn't seem to care. Or rather, they DID care...they preferred to be wrong! I get the same sorts of responses with these math issues of mine: seems like people would rather be wrong, and rely upon me to "know what they mean".

We've spoken before, I think, about how people allow themselves to use poor language skills, relying upon their listener to simply "know what they mean". This is the same sort of corruption, I think. I'm supposed to just magically "know what they mean". I like to think that the better idea is for the speaker to think about what they're trying to say, and say what they mean. That way, miscommunication is minimized. At the end of the day, I know me: I hardly ever know what anyone means! :)

I'm all alone again, aren't I?


  1. I have enough trouble with my own basic math without critiquing (sp?) other folks.....math talk just goes over my head with a blub blub blub..sort of like sports talk. I have probably made some of those mistakes and a few more besides.

    1. I hear you; we all make mistakes and every one of us has topics that go in one ear and out the other, or don't make it into our ears at all. But when a person's primary job is communications, and they're trying to sell me something, I'd think that they'd endeavor to get their message(s) correct.

  2. I hate it when people say "less" when they really mean fewer... Especially at the supermarket... It should be "20 items or FEWER". Not less.

  3. Being math-minded, I notice things like this ALL THE TIME, and it bugs me to no end. I make mistakes (occasionally, *cough*) when I speak or write, but I'm also not trying to sell anyone goods or services. Like you, I point these things out to my wife, and she chuckles at them sometimes, although maybe more to humor me.

    "Eight times lower" would mean, if I'm not mistaken, that the object in question has a value of -7 times the original: x - 8x = -7x

    Yes, a new decade, century, or millennium starts when the year has a 1 in the ones digit. Why? Because there is no year 0 - it went from 1 BC to AD 1 (or, if you want to use the new terminology, 1 BCE to 1 CE). Bottom line, I think, is that people like to see the numbers flip to zeroes.

    "Multiplied our efficiency by 50%" I haven't heard, but it sounds like government-speak.

    "Divided by" is NOT the same as "cut by" when referring to numbers. Oi!

    People would rather you know what they mean, as opposed to using the correct words, because it requires them to think less.

    1. I always feel like I'm the only one who sees these things. Glad to be wrong!!

  4. These things make me nuts, too, STG. It's pandemic in advertising. And abused in "news" stories. All it does is show those of us who actually paid attention in math class why Americans are in the low ranks of math education worldwide.