Letter: Method used to teach math is flawed

To the editor,

I have taught advanced college-level general chemistry using the same texts and standards of Harvard and Yale, but as a professor in a community college in the New York City system. All high school students with an 80 average and above went to a four-year senior college. We only got students who had an average of 79 and below, and I think the latter grades were somewhat inflated. What to do?

All incoming freshmen were tested in reading, writing and math. Over 97 percent failed. Most students were required to take two semesters of no-credit remedial course and we had to sell the concept of giving up a year of their life to learn what they should have learned in high school, but it worked.

Teaching chemistry at the most advanced level required 60 percent math and I have become an expert at teaching to use the necessary math.

Now, to the point of my letter. The scores of students in the area schools are horrendous. Only 40 percent can reach a minimum standard in math. The teaching system is flawed — not the teachers — but the method they must use to teach math. Simply put: go back 40 years.

Some suggestions: memorize basic addition and all the multiplication tables; all students should be given a simple calculator, but only to use to check out their previous hand-done assignments. Start in first grade; very important, teach students to estimate. Example: 8+6. Estimate it is over 10. Hence, borrow 2 away from 6 leaving a 4. 14 is the answer; reduce the use of fractions. The stock marker three years ago went to decimal notations. We buy meat at $4.21 a pound. Mileage is now decimal (4.3 miles). Still teach fractions but minimize; learn the giveaway of the word “of” — it means to multiply. Example: What is 4/7 of 3/9. Don’t invert the latter as a division, multiply; forget all those horrendous zeros and steps in long division. Estimate your first step, check by multiplication, shift everything one notch and go on. One minute versus the five minutes now used; multiply — if the number is bigger than 9 use your fingers to carry. Example: 27×6. 7×6 is 42, put pressure on four fingers and add 4 to 6×2 = 12 + 4 carried = 16 to get 162. A little carry note can be used if preferred; forget the remainder in long division, carry it out one more decimal and make sure your roundoff is less than 1 percent. Again, check your answer with your calculators; very important — learn to use descriptive units. Example: There are 454 grams (g) in a pound (16). Think 454 g/16 or better yet 1/454 16/g.

Teaching advanced chemistry includes pH (measure of acidity). This is a negative log function. In 20 minutes I taught my students how to do the log of any number in the world in their heads — no tables, no calculators — in 10 seconds. A student asked me, “Why do it your way? All I have to do is push a button on my calculator.” I replied, “What if you were walking an old lady across a wide street and she asked, ‘Do you know the log of .000015?’ In eight seconds you can answer.”

John Tietjen


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