The idea of the DOW Bee Mental Math Project stems in part from one of my fondest memories — a game my father used to stimulate thinking when my brother and I climbed into the back seat of the family car. We would no sooner hear the engine start than our father asking us “the” question.
Naturally, we would compete to be first to belt out the correct answer and upon hearing it, Dad would proceed to give voice to one problem after another until we reached our destination. On many an occasion, of course, we’d fail to get the right answer so he’d repeat the problem until at least one of us discovered the error of his way.
As time passed, not only did the tempo of the problems accelerate, they became increasingly difficult because they required a reasonable command of fractions, decimals, squares, and square roots. As described, the game was not only engaging and entertaining, it was highly competitive at least in the sense that at the time nothing was more motivating for me than being given the opportunity to best my older brother at anything.
I was reminded of that childhood experience several months ago when I stumbled upon Professor Arthur Benjamin’s The Secrets of Mental Math, a book I wish I had had in hand when I taught math to elementary and junior high school students back in the late 60s and early 80s. The text was so inspiring that I came out of retirement to introduce my grandson’s seventh grade class to not only a half dozen of the mental math tricks contained in the book’s opening chapters but the concept of calendar calculations. It would be an gross understatement to say that he and his classmates were excited when I asked them if they’d like to know how to calculate the weekday they were born on.
A month later I found myself sitting in my daughter’ s living room converting random calendar dates as far back as the 1500s in a notebook I’d brought along with me to entertain myself. A young man, Robert (not his real name), stepped into the room and inquired as to what I was doing. One thing led to another and I found myself explaining the underlying algorithm. Not just a little taken by the idea, he shared the following story related to a job interview he’d recently undergone.
An experienced aerospace engineer with a degree from Ohio State University, he thought himself well prepared to answer the dozen or more questions the interviewer asked. In fact, up until the very end he thought he had pretty much aced the interview. That perception changed, however, when the employer handed him a pad of paper and a pencil and asked him to do a set of relatively of simple multiplication and division problems without the use of a calculator. Robert picked up the pencil to do as he had been asked but had to abandon the task a minute or so later when he realized he couldn’t complete it.
As shocking the discovery was to him and informative as his story was to me, it turned out to be less an eye opener than the revelation that followed. The hiring official smiled before he shook his head and chuckled out loud at Robert’s obvious embarrassment and discomfort. It was then that he revealed that he had apparently assigned the same task to more than a half dozen candidates and all but two had apparently failed the test just like Robert.
With my childhood and Robert’s experiences in mind, imagine yourself seated at the dining room table listening to your family discuss plans to celebrate a sibling’s next birthday only to hear your 10-year-old nephew casually declare that his birthday will fall on a Wednesday this year, Friday next. You look in his direction as he reaches out to pick up another dinner roll. He has gotten your attention. Naturally you wonder if his assertion was an accurate one.
You reach in your pocket and pull out your iPhone, activate the calendar app and discover that your brother’s birthday will, indeed, fall on Wednesday this year. You then spend the next 10 seconds fast forwarding the calendar to the following year only to confirm that next year his birthday will occur on the aforementioned Friday.
“How did you know that your uncle’s birthday will fall on a Wednesday this year?” you ask.
“It’s magic,” he responds with an all knowing smile as he takes a big bite out of that now well-buttered roll.
As you will soon discover, a command of DOW mathematics not only provides a fascinatingly efficient and effective means to make future plans but to recount the past. In the process it turns mathematics from an all too often, technologically driven passive mental activity into a proactive one. One can, of course, always refer to a calendar, just like engineers refer to their calculators, but it is so much more gratifying to be in the unique position to determine the day of the week (DOW) without referencing one.
As for children, who among them can help but get a real sense of accomplishment and self-worth when they will be the only one seated at the table who has no need to reference a printed or computer generated calendar. What is more, who amongst those seated with her/him can help but be impressed by such a bright youngster.