# The difference between “require digit”, “requires a digit” and “requires digits”

For example, we have few addresses like:

• "Box 111"
• "Some Rd Suite 1"

And we also have addresses that without any number:

• "Some Rd"

So to communicate that we prefer the address with numbers, what should we say?

1. digit
2. a digit
3. digits

Update:

Will there be any difference if we change "digit" to "number"?

1. number
2. a number
3. numbers

Update:

"contain digit/number" is a literal translate from Chinese. In Chinese, "digit/number" is used as an abstract concept here so no need to specify the quantity.

Are there the same thing for English, or we have to specify the quantity and modifiers to concrete it?

-
what are you asking? digits for the address? phone? etc. – Paul Amerigo Pajo May 18 '11 at 6:08
What if the address really doesn't have any digits in it? – Steve Melnikoff May 18 '11 at 10:55

The most familiar way of saying this for many English speakers is to use "number", as in Awe's suggestion

A valid mailing address requires a number.

Or, change the wording to say what the person must do

You must include a number in the mailing address.

similar to this real-world set of address guidelines for street problem reporting. These instructions happen to also show Will Martin's suggestion to show examples of valid input.

To address the other possible ways of saying this phrase:

• Both Options 3 ("address requires digits"/"address requires numbers") will confuse some readers who wonder if least two digits are required.
• Option 2 ("address requires a digit") will confuse some readers because "digit" is rarely used except with a quantity, as in, "Enter a 5-digit ZIP Code."
• Option 2 ("address requires a number") is the best option. Most readers are likely to interpret this as "Enter one integer, like 1 or 111, that contains one or more digits."

To summarize, in English, there is no obvious way to express "digit/number" as an abstract concept. For a technical audience, you may need to include more modifiers to be clear, but for most audiences, a phrase like "a number" is probably the most abstract or general way of referring to a numerical value.

-
Your summarization cleared my doubt. Thanks. – Cheng May 18 '11 at 18:37

Option #1 is definitely NOT the best; you must put an article before a singular count noun.

Options 2 and 3 are technically correct, but sound strange - I would rephrase this sentence as "A valid mailing address must contain at least one digit."

My apologies for the quality of that link - it's hard to find a freely linkable style manual (they're all behind paywalls.)

-
Can we say it contains one digit, so it meets the requirement of "contain digits"? – Cheng May 18 '11 at 6:23
"Contain" requires a plural subject - you could say "Addresses contain digits," but not "Address contain digits." Easy rule of thumb: there should be one S at the end of either subject or verb - "addresseS contain" or "address containS." – MT_Head May 18 '11 at 6:35
But to answer your question: if you say it "must contain at least one digit", then one or more digits will fit the rule. If you say it "must contain one", then what if there are two or more? The reader will be unsure. – MT_Head May 18 '11 at 6:38
"contain digit/number" is a literal translate from Chinese, which "digit/number" is used as an abstract concept here so no need to specify the quantity. Are there the same thing for English, or we have to specify the quantity and modifiers to concrete it? – Cheng May 18 '11 at 7:00
"Digit" in English refers to the individual characters (0 through 9), or to the "place" that they occupy: the "tens digit", the "hundreds digit", etc. In either case, the item is singular - the word "digit" also means "finger" (that's actually the original sense of the word.) "Number" refers to the mathematical concept represented by one or more digits - 1 is both a digit and a number; 10 is a two-digit number. – MT_Head May 18 '11 at 7:05

Number and digit has a slightly different meaning. A number can contain one or more digits. The number `1` consists of one digit. The number `11` consists of two digits.