Just before Christmas, my sister-in-law’s family was visiting in Atlanta, and my nephew in 6th grade was studying for a test on long division and calculating reciprocals.
I had not thought about long division myself in a long time. I remember making the argument to my teachers that calculators obviated the need to do long division (and any other tedious arithmetic) by hand. The typical response was, “What if you don’t have a calculator?” My 9-year-old brain wasn’t witty or sharp enough to come up with an answer that wouldn’t get me put in the corner for sassing, so I shut up and went back to work.
Now, at 37, I’ve reconsidered the situation. And now, with the wisdom of age and years of PhD-level STEM education, I’m even more certain that learning long division by hand–at least the way I learned it and my nephew apparently was–is D-U-M-B.
The algorithm above that schoolkids have been learning for generations is a way to find precise answers to division problems. It is a straightforward process that kids can learn by the numbers. Simply follow the steps, turn the crank, and you’ll get the answer.
Unfortunately, learning this process misses the point, if the point is understanding mathematics. The turn-the-crank method taught in school right now does nothing to help kids understand why it works.
If the point is to have a useful skill, in what circumstance would the average person find it useful to get precise answers to these kinds of problems, and not have a calculator? We have more computers and calculators available than ever.
If we want our kids to gain a truly useful skill, and a deeper understanding of mathematics, we should teach them how to do accurate estimation rather that rote process.