Find N in the crowd-A A +A
Wednesday, February 20, 2013
One idle afternoon, Sun.Star Cebu sports editor Mike Limpag did some math, a thing he is not fond of but can do passably if given an entire day. He calculated the Sinulog grand parade crowd that can fill the 1.1-kilometer stretch between the Fuente Osmeña rotunda to the intersection of Osmeña Blvd. and P. del Rosario St. in Cebu City.
Every year, police and festivity organizers would estimate the mammoth crowd that fills the main streets of Cebu City during the grand procession and the grand parade in millions.
In 2010, then Police Regional Office (PRO) 7 director Lani-O Nerez estimated the crowd during the Sinulog grand parade at eight million. In 2010, Cebu island’s population was pegged at 4.1 million. The grand parade is concentrated on six kilometers of roads in Cebu City.
Mike made his calculation:
The abovementioned stretch on Osmena Blvd. is 1,140 meters long and 30.19 meters wide. Its total area is 35,340 square meters, which, converted to square foot, is 116,622 sq.ft.
A square foot is 144 square inches. The size of an iPad version 1 is about 69.44 square inches. “If we allocate one square foot to an individual, can two guys stand on an iPad? That means at its maximum area, the parade will have 116,622 participants at its widest point for 1.1 kilometers.”
By his calculated estimate, the maximum number of people that can fill 5.7 kilometers of the Sinulog grand parade route would only be 588,110.
I bring this up because of the letter sent to Sun.Star Cebu editors by the grade six math class of Frobel iSchool (on V. Rama Avenue, Cebu City) on our reports about crowd estimates. The kids enumerated our stories that reported about crowd estimates whose numbers they did not agree with.
They had computed “doubtable figures” that we had reported such as the 2.7 million and 1.1 million who joined the Sinulog solemn procession this year and last, the four million spectators during the Sinulog 2012 grand parade, the 113 tons of post-parade trash, and the 25,000 people at the United Nationalist Alliance grand rally at Plaza Independencia.
Their letter showed a formula on crowd estimation. Like a math problem, it had a given and a solution. I was just relieved that they did not ask us to find N. It would have taken us a week, or on our slow days, a decade or maybe never, to find N.
“To estimate the attendees of events, the first thing to get is the area or space available then multiplied by the density of people possible for that space,” the math kids suggested.
They showed the formula, with lots of parentheses and equal and X signs. They experimented with putting six people on one square meter and this was “very tight already.”
We tried it ourselves. Only four of us—two large, one medium and one small individuals—fit one square meter. And boy, were we tight. We were kissing each other’s nape.
So, using their formula, the crowd during the Sinulog 2012 grand procession should only have been 360,000 in a stretch of three kilometers. “The figure of 2.7 million is not only too high, but also impossible (this would mean 45 people/sq.m.),” the math kids said.
The police, who give the crowd estimate to reporters, can learn from these Frobel kids. Sir Chief, please get a pen and a paper and turn on the calculator function of your mobile phone. Check the area available for the rally and solve for the people that can fit one square meter (two only if dagko og tiyan) and find N.
The math kids were polite and did not wish to offend the editors. “We would appreciate any corrections you have.” No, you’re correct, kids. You find N for us.
Published in the Sun.Star Cebu newspaper on February 21, 2013.