But it always adds up to a bad day.
Dear Word Detective: Countless times I’ve heard the phrase “to do a number on” someone or something, meaning “to affect strongly, often negatively.” I wonder how that came into our language. It seems like a usage that sprang up with the ’60s and ’70s counter-culture, maybe originating as musicians’ slang. — Slidedaddy.
“Do a number on” is one of those stealthy little phrases that you pick up without really thinking about it and then use for years, blissfully never questioning what the “number” might be or how one “does” a number in the first place. Of course, most slang spreads in just this casual, unquestioning fashion; few of us would think to ask a friend exactly what “number” his latest fender-bender “did” on his car. Asking is uncool. One interprets such things from context, and it’s pretty clear that nothing was ever improved by having a “number done” on it.
“Number” is, as you can imagine, a very old word. It first appeared in English around 1300 with the meaning “the precise sum or aggregate of a collection of individual things or persons” (“He sayth that then shall the nomber of sore and sick beggers decreace,” 1529). The root of “number” was the Latin “numerus” (meaning “sum” or “total,” which also gave us “numerous,” “numeral,” “enumerate” and other modern English words), which in turn came from a root meaning “to divide or distribute.” The use of “number” to mean “symbol of arithmetic value” appeared around 1400.
As most core English words do, “number” has acquired a wide range of figurative and slang senses. One of the older uses of “number” in slang is “playing the numbers,” i.e., betting in an illegal lottery, a use common in US cities since the mid-19th century. Also in the 19th century, we began to use “number” in a very vague sense to mean “one of something,” such as an article of clothing (“[A]n exquisite but throat-high ‘little number’ redeemed by lumps of jade,” 1953), or even a person (“Have you seen a little blond number named Adeline?”, 1955).
In the mid-19th century, we began to use “number” as theatrical slang to mean “a particular item in a program of musical entertainment,” most likely because items in a printed program given to audience members were often literally numbered. This led to the use of “number” to mean “a song” as well as, at least within the theatrical community, to mean a “bit” or “routine” associated with a particular performer. This led in turn, by the late 1960s, to the use of “number” to mean “manner or routine pattern of behavior” (“Bob always does his poverty number, but he actually has pots of money.”).
All of which brings us to “to do a number on,” which first appeared in the African-American community in the late 1960s meaning “to act with destructive impact on” (“There were about four or five cats doing a number on (beating hell out of) a Puerto Rican,” New York Times, 1972) or “to criticize severely.” This slang sense seems to combine the intentionally vague use of “number” to mean an unspecified “something” with the sense of “a personal routine or characteristic behavior,” in this case ranging from an angry tirade to a physical beating. The phrase “do a number on” has been tempered somewhat as its use became more mainstream, and it’s often now used to mean simply “affect negatively” (“Frigid temperatures can do a number on your plumbing if your pipes aren’t properly insulated,” 2010).