To readers who want to use for business orientations or online classes my analogy of salary increases with the spread of the virus, go ahead. See “The math behind the virus’ dangerous spread,” which was published last May 21.
I often have used that linear versus exponential growth illustration in algebra classes prepandemic, but the idea is not original.
An ancient version is the wheat and chessboard problem, supposedly posed by the inventor of chess to a ruler in India. The latter, the story goes, fell in love with the game so much he offered the former anything he wanted.
The chess master asked for grains of wheat: one for the first square, two for the second, four for the third, and so on, doubling the number, until the 64th square. The ruler soon realized that the kingdom would go bankrupt less than halfway through.
Readers have also asked for more math pointers relevant to the new coronavirus disease (COVID-19) pandemic. Here is another:
Supermarkets and grocery stores rightly institute thermal scans and face mask checks before allowing customers inside.
But since the number of customers inside at any one time is limited, people have no choice but to line up outside. And there’s the rub, because social distancing outside is not strictly enforced.
Health authorities warn that we need to keep a distance of at least 2 meters from each other. Recent research questions if this would be safe enough. See US molecular biologist Tina Hesman Saey’s article “Six-foot social distancing will not always be enough for COVID-19” on the Science News for Students site.
Sneezing and coughing are potential ways of spreading the virus, and so are singing and talking.
Many would-be customers line up outside the store, dutifully wearing their masks. But they sit or stand only a couple of feet away from one another.
In a webinar for a business group, one participant we’ll call Annie said, “When I was lining up for groceries at the neighborhood supermarket, the elderly lady behind me appeared to be hard of hearing. Her husband was talking and all of us could hear the entire saga, but she kept on saying, ‘Huh?’ so that he finally had to raise his voice. We were trying to ignore them, but I wish she would just stay home and let him do the shopping.” “If the lady had a cloth mask, it would muffle sound,” I said. “Could you really hear everything the husband said?”
“Quite clearly, even with the mask,” Annie said.
“Were the couple right behind you?” I asked.
“No, there were maybe two people in between us,” Annie said. “But he was really loud.”
“If there were two people in between you and the couple, then you would be separated by at least 6 meters: 2 meters from you and person A behind you, then 2 meters from A to person B, then 2 meters from B to the couple. You must have a fantastic auditory sense,” I said. “I have sensitive hearing,” Annie said. “But you know, with a little bit more reaching out, I can already touch the wife. I was tempted to turn around, and tap her on the shoulder to shush her.”
I asked Annie, “Can you show me how far away you were from person A behind you?” Annie motioned with her hands and showed a distance barely a foot and a half apart.
“Do you think that is 2 meters?” I asked her, with a sinking heart. Annie shrugged.
“That’s how far we were when lining up. The store guard didn’t say anything.”
“Two meters is more than three times the distance of 2 feet,” I said. “Two meters would be around 6 feet and 7 inches. If you were truly 6 meters apart, then that would be almost 20-feet apart.” Horror crossed her face. “Huh? I thought a meter was just a bit more than a foot!”
Two meters would roughly be the length of a double bed, the arm span of a tall adult, four desk spaces in a classroom, two large shopping carts placed end to end.
BBC News advises people who go out to bring a broom (more like a mop with a long handle in our context, since our ordinary brooms are barely a meter long) to measure distance.
Moreover, “if you’re close enough to elbow-bump a greeting, you’re not keeping a 2-meter distance,” Saey says. “At this distance, tiny spit aerosols expelled by talking can easily reach another’s face.”
Queena N. Lee-Chua is with the board of directors of Ateneo’s Family Business Center. Get her book “All in the Family Business” at www.lazada.com.ph or call National’s Jennie Garcia at 0915-421-2276. Contact the author at blessbook.chua@gmail.com.