When used as nouns numbers can be singular or plural.
Seven is a lucky number. -- as a noun 'seven' is singular.
Nine times nine is 81. -- same as above.
Nine eights are 72 -- eight is plural so use a plural be verb.
When numbers come before nouns (as determiners) then the verb can be singular or plural:
Three monkeys always escape from their cage.
or
One monkey always escapes from his cage
Precede Obviously!
If "the number" is the subject of a sentence or clause, the verb in the same sentence or clause should be singular in form, but if "a number" is the subject of a sentence or clause, the verb in the same sentence or clause should be plural in form. The rationale supporting this rule is that the phrase "the number" implies that only one number is being considered, but "a number" implies that more than one number is likely.
examples of a numeric number.
A number is a noun as a word for a number or a quantity. Examples: The table is set for six. Volume two has arrived at the bookstore.
2468
Precede Obviously!
All numbers from 1 to 998 precede the number 999.
key
hash
Pronoun-verb agreement requires a correct match between a pronoun and a verb based on number (singular or plural).A singular pronoun requires a verb for a singular subject.Example: She is expected at noon. (singular subject pronoun)A plural pronoun requires a verb for a plural subject.Example: They are expected at noon. (plural subject pronoun)
If "the number" is the subject of a sentence or clause, the verb in the same sentence or clause should be singular in form, but if "a number" is the subject of a sentence or clause, the verb in the same sentence or clause should be plural in form. The rationale supporting this rule is that the phrase "the number" implies that only one number is being considered, but "a number" implies that more than one number is likely.
There is a hyphen in phrases like "100-year", because they precede whatever they are modifying, like a "100-year flood". In general, two-word phrases are hyphenated when they are used as adjectives and precede the term they modify.
The absolute value of a number is the distance it is from zero on a number line. It is written as the number without any sign.
An apostrophe (') should precede a number with leading zeros to ensure that the zeros will be displayed in a cell.
There is only one rule of which I am aware -- Subjects and verbs must agree in number and in person.
This is not correct for a sweet 16. Your serial number is incomplete. The gun should have a letter and or letter/number associated with the serial number to determine age. The letter should precede the 99230 or be above it
You use the number of examples that you feel are necessary to illustrate your point. This also depends upon how long your examples are. If you are giving examples of words that start with the letter a, you can give lots of them, since each example is a single word. If your example requires five sentences of explanation, then perhaps you should use only one per paragraph.