Math for Grownups

Math doesn't have to be your BFF, but you can get along in public

Math Secret #1: There’s More than One Way to Skin a Math Problem

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math secret restaurant

Photo courtesy of Steve Snodgrass

The more I talk to people about math, the more I hear this refrain: “I don’t like math, because math problems have only one answer.”

Peshaw!

Okay, so it’s not such a crazy idea.  Most math problems do have one answer (as long as we agree with some basic premises, like that we’re working in base ten).  But math can be a very creative pursuit — and I’m not talking about knot theory or fractals or any of those other advanced math concepts.

I have a friend who is crazy good at doing mental math.  She can split the bill at a table of 15 — even when each person had a completely different meal and everyone shared four appetizers — without a calculator, smart phone or pencil and paper!  This amazed me, so I asked her how she does it.  And what I discovered was pretty surprising. She approaches these simple arithmetic problems in ways that I never would have thought of.  She subtracts to solve addition problems, divides to multiply.  And estimation? Boy howdy, does the girl estimate.  In other words, she gets creative.

(She also has a pretty darned good understanding of how numbers work together, which is probably the biggest reason she can accomplish these feats of restaurant arithmetic.)

While there may be one absolutely, without-a-doubt, perfectly correct answer to “How much do I owe the waiter?” there are dozens of ways to get to that answer.  Problem is, your fourth grade math teacher probably didn’t want to hear about your creative approach.

See, when we learn math as kids, we’re focused on computation through algorithms.  (In case you’re not familiar with the word, algorithms are step-by-step procedures designed to get you to the answer.)  You did drill after drill of multiplication, long division, finding the LCM (Least Common Multiple) and converting percents to fractions.  But nobody ever asked you, “How would you do it in your head?”

The good news is that now you’re all grown up.  There’s not a single teacher who is looking over your shoulder to see if you lined up your decimal points and carried the 2.  You can chart your own path!  And when people are given this freedom, they often find really interesting ways to solve problems.

Don’t believe me?  Try this out: Add 73 and 38 in your head.  How did you do it?  Now pose the question to someone else.  Did they do something different?  If not, ask someone else.  I will guarantee that among your friends and family, you’ll find at least three different ways of approaching this addition problem.

So, let’s do this experiment here.  In the comments section, post how you solved 73 + 38 without a calculator or paper and pencil.  Then come back later to see if someone else had a different approach.  If you’re feeling really bold, post this question as your Facebook status, then report the results in the comments section.

And while you’re at Facebook, be sure to visit and like the Math For Grownups Facebook fan page!

My Math Story

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math story geometry

Photo courtesy of Aaron Escobar

The biggest fights my father and I had were about math.  I kid you not.

The year was 1984.  I was a junior in high school, taking Algebra II.  Radicals were kicking my scrawny, little butt.

(Remember radicals?  They look like this: [pmath]sqrt{24}[/pmath]. In Algebra II, you mostly learned to simplify them, as well as add, subtract, multiply and divide with them.)

My father wanted to help, and he had the patience of Job.  But he was not great at accepting that I didn’t understand.  And I wasn’t great at controlling my emotions.  I hollered, cried and probably threw things.  Somehow, I got the impression that my dad thought I couldn’t do math, and I did what any strong-willed girl will: I dug in my heels.

That’s when I started drinking coffee, actually.  I was so determined to show my dad–and my Algebra II teacher, Mr. Gardner–that I got up at 4:30 a.m., sat in my dad’s easy chair with a cup of coffee and a stack of sharpened pencils, and did problem after problem after problem.

I did every single radicals problem in the textbook.  And then I did them again. I took what Mr. Gardner and my dad taught me and figured the darned things out.  It took time, but I was determined not to give up.

Why on earth would I do this?  Well, I’m stubborn, for one.  But probably the biggest reason is Mrs. Ivey.  She was my geometry teacher the year before, and she changed my perspective about math.  You see, before then, I knew I couldn’t do math.  Mrs. Ivey convinced me that I was wrong.

She and my father are the reasons I majored in math.  I found out I’m a math teacher, not a mathematician. (Sometimes we’re one or the other.)  I’m fascinated by the ways people choose to do math, not by complex computations or proofs.

Math geeks aren’t always born.  Sometimes a teacher inspires us.  Sometimes we’re dragged kicking and screaming. And sometimes we just learn to deal with math–because we have to.

What’s your math story? Share it in the comments section!