Teaching math: Girl Scouts and Pizza

The miniature Girl Scout delivering cookies to my front door informed me that my total was twelve dollars. I recognized her as a first grader. I had been a sub teacher a few times in her class. I couldn't resist the urge to slip into my teaching mode.

"Hmmm, let me see," I mused, sorting my currency, "Here's a five and another five and two ones, How much is five plus five plus two?"

A look of anxiety spread across her face. I could almost read her thoughts, since it was a question she had obviously not expected to hear outside of the classroom. It was a tense moment.

Human compassion -- plus the realizaion that my cookies might be in jepoardy-- softened me.

"Let's count it together, " I said, not willing to give up the teacher role completely. "Here's five and five. We can count dollars just the same way we count fingers. Five and five is . . . ten! . . . and two more? let's count, ten . . . eleven. . . twelve. . . is that it?"

Her affirmative smile and nod spelled relief. I really hate to see a six and a half-year old with sweaty palms, especially when she's holding my cookies.

This experience and others give me the impression that kids make very little connection between school lessons and real life. In many cases the relationship may be tenuous at best. Sometimes, as teachers, we have the opportunity to relate classroom subjects to the actual interests of the students. I think we should do so whenever possible.

So how do we know what they are interested in? Food is always popular, so I often teach fractions with pizza. Every fourth fifth and sixth grader can relate to sharing a pizza with a friend or two, or three. I get them to think about this . -- even to the point of naming the friends and choosing the toppings (pepperoni, sausage . . . no anchovies).

Drawing diagrams on the board to represent the scenarios of several students quickly demonstrates the concept that sharing with one friend results in big pieces (one half) and sharing equally with several friends reduces their portion considerably.

Recently I was quite surprised to hear a teacher i know and respect say that we must teach math with rote memorized rules because elementary level students cannot grasp "abstract" underlying concepts. BALONEY! Let me show you another pizza example (with no baloney on it). This time my extra large salami and mushroom pizza has been cut into sixteenths. I tell the class that two persons in the class each got four of those sixteenths and I got eight of those same sized pieces. "NO FAIR!" they exclaim," you got half of the pizza." they had grasped the underlying concept: those skinny pieces really add up.

I believe that it is the concept that makes the rule understandable AND it was a lot more fun tthan trying to get them to memorize: TO EXPRESS A FRACTION IN IT'S SIMPLEST FORM, DIVIDE THE NUMERATOR AND THE DENOMINATOR BY THE HIGHEST COMMON FACTOR.

Of course you will find some students who can grasp this right away, but most respond to the rote route such as this with a blank stare that is the facially expressed equivalent of a telephone busy signal . . . you are not reaching the person to whom you wish to speak.

A few weeks ago I returned to a school where I had been given the chance of using my pizza fractions in a fourth grade group. The teacher of the class recognized me in the teacher's lounge and loudly complimented me on my work in teaching a lesson on equivalent fractions. "They all seemed to catch on," she said brightly, "How did you present it?"

"It was the old pizza ploy,," I explained "Basically, I followed the suggestions in the manuel, then I added some Mozzarella and bell peppers." She nodded seriously, "That's what I usually do, too."

Other teachers regarded me with mixed admiration and the kind of reticence usually reserved for the terminally strange.

I think I'll go reward myself with a Girl Scout cookie . . . maybe even one and eight sixteeenths of a cookie.