Yes, the passage you quoted from a United Nations report is one of the exceptions to the general rule that the numbers 10 and below should be spelled out, as discussed in my essay,
“Your handling of numbers and time reflects the clarity of your thinking,” that I posted in the Forum way back in May 2010.
In expository writing and in journalism in particular, the general rule for writing numbers is specifically as follows:
(1) numbers from 1 to 10 should be written as words when used in a sentence: “The customer ordered eight red shirts and five blue ones, but returned three browns”; and (2) numbers from 11 upwards in a sentence should be written in figures: “The professor discovered to her dismay that 12 of her pupils were absent, and that 546 of the entire student population did not make it to their classes either.” And if perchance the sentence has numbers ranging from 1 to any number higher than 10, the two rules above still hold even if it means mixing figures and spelled-out numbers: “We counted a total of 800 words in her essay and found ten misspelled words and 17 wrong word choices.”
However, in the second to the last paragraph, that essay of mine made it clear that scientific, mathematical, statistical, and physical sciences writing is an exception to that general rule:
(1) We should use figures and not spell out numbers immediately before a unit of measure: “a 10-minute wait,” “a 3-3/4 cm. length of tape,” “16 Megahertz on the FM band”; (2) We should use figures and not spell out numbers that represent statistical or mathematical functions or formulas: “divided by 6,” multiplied by 9,” “a ratio of 50:1,” “8% bigger”; and (3) We should use figures and not spell out numbers that represent time, ages, money, sizes, scores, and points on a scale: “at 12 midnight,” “4 years old,” “$9,” “5 cm. x 12 cm.,” “73:69,” and “Intensity 5 on the Richter Scale.”
Evidently, this exception to the rule is what the United Nations report followed for the passage that you quoted.
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ADDENDUM 14 YEARS LATER TO THIS DAY (September 25, 2024): For Forum members, particularly English teachers, who are keen on truly enriching their grasp of how to precisely write numbers in their English expositions, I strongly recommend checking out Brenda Kovich's fascinatingly detailed website on "Writing Rules for Numbers in Standard Form and Words" (
https://enjoy-teaching.com/writing-rules-for-numbers/).
--Joe CarilloIMAGE CREDIT: ENJOY TEACHING WITH BRENDA KOVICH