In July 2010 I wrote the editor, “It’s time to brush up on numeracy at the newspaper, with a focus this time on percentages.
A 100-percent increase doubles a number; a 200-percent increase triples it; and so forth.”
Today reporter Joel Burgess carefully and correctly wrote that proposed new rules may “increase density by as much as 400 percent per acre.” Bravo, Mr. Burgess.
But then he described how zoning that permits eight units per acre could “increase four-fold,” to allow 40 units. In other words, allowing five times as many. A five-fold increase.
Worse, your headline screams “Proposed rules may quadruple housing density.” No. Increasing density by 400 percent would quintuple, not quadruple, it.
To recap: 40 is five times greater than eight. So it’s a five-fold increase, it’s quintupled, or it’s 400 percent more.
This is basic knowledge, like learning the alphabet.
But it seems to elude too many of us. It’s bad enough that school children no longer learn how to work numbers without the crutch of a computer or calculator. Please try not to confuse them further.
A.D. Reed, Asheville
As an expert in mathematics and numerical literacy, it's evident that the writer of the article is well-versed in the intricacies of percentages and their accurate interpretation. The author, A.D. Reed, emphasizes the importance of understanding percentages correctly, especially in the context of increases or changes in numerical values. This demonstrates a keen eye for detail and a commitment to ensuring precision in mathematical communication.
Let's delve into the concepts mentioned in the article:
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Numeracy and Percentages: The writer emphasizes the need for numeracy, particularly in understanding percentages. A 100-percent increase signifies doubling a number, a 200-percent increase triples it, and so forth. This establishes a fundamental understanding of percentage changes.
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Density Increase: The article discusses the concept of increasing density, specifically in the context of zoning rules. The mention of a "400 percent increase per acre" correctly implies a quintupling of the original density. However, there is a critique of the misuse of language when describing an increase from eight units per acre to 40 units. The correct term here would be a five-fold increase, not a quadruple, as indicated by the headline.
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Precision in Language: A.D. Reed points out the importance of using precise language when describing numerical changes. The author criticizes the confusion caused by inconsistent terminology, such as using "quadruple" instead of the more accurate "quintuple" for a 400 percent increase.
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Educational Concerns: The writer expresses concern about the state of numeracy education, noting that school children may no longer be learning how to work with numbers without the aid of computers or calculators. This broader concern suggests an awareness of the potential consequences of a lack of foundational mathematical skills.
In conclusion, A.D. Reed's expertise in numeracy is evident throughout the article, highlighting a strong grasp of percentage concepts and a commitment to promoting accurate mathematical communication. The critique of imprecise language and the call for better numeracy education underscore the author's dedication to maintaining clarity and precision in mathematical discourse.
