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Use of Numbers

It can be difficult knowing when to use numerals and when to spell them out.

Incorrect: The book highlights major events in the 1960's in the American history.
Correct: The book highlights major events in the 1960s in the American history.
Incorrect: Students need to hand in 2 copies of their assignment.
Correct: Students need to hand in two copies of their assignment.

Rule to Remember

Spell out numbers below 10 in MLA style or below 100 in APA style.

Correcting Wrong Use of Numbers

Numbers between 1 and 9 should be spelled out (in MLA style). When the writing sample uses numbers infrequently, or if APA style is followed, numbers between 1 and 100 should also be spelled out.

If two or more related numbers are used in a sentence, one below 10 and one a bigger number, their use should be consistent. They can either be spelled out or written as numerals.

Correct: We have a large family. My sister has 5 children. My great grandmother, however, had 19 grandchildren before she died.
Correct: We have a large family. My sister has five children. My great grandmother, however, had nineteen grandchildren before she died.

If, however, the numbers refer to two different things, they can be written differently.

Numbers at the beginning of the sentence should also be spelled out with the exception of years:

Correct: Two-thirds of the class scored in the mid 80s in their final exam.
Correct: 1564 is the year when Shakespeare was born.

Rule to Remember

Spell out numbers at the beginning of the sentence, with the exception of years.

Numbers that represent years, days of month, pages, chapters, street addresses, route numbers, percentages, temperatures, and telephone numbers should be written as numerals.

Correct: In all, 78% of voters backed the changes to the constitution while 17% were undecided. Those against the changes had 5% of the votes.
Correct: Classes at NIU begin no earlier than 8:00 a.m.
Correct: Sherlock Holmes lived at 221B Baker Street, London.
Correct: Gas prices are now more than $3.00 a gallon.
Correct: The Battle of Gettysburg ended on July 3, 1863.

Numbers should be written as numerals when accompanied by abbreviations such as lb, in, mph, rpm, etc.

Correct: More fuel efficient cars with at least 30 mpg or better are much easier to sell.

Written numbers such as dozen, hundred, thousand, or million should be expressed in singular form when there is a specific number or quantifier preceding it, as in

a couple dozen

several hundred

four hundred

twenty thousand

a few dozen

fifty million

Rule to Remember

Do not use an apostrophe to form the plural form of a numeral.

However, those same numbers should be expressed in plural when there is no preceding number, or when the numbers are used to express generalized statements.

Correct: I looked at dozens of websites during my research process.
Correct: Hundreds of people attended the exhibition opening.
Correct: Stonehenge has stood for thousands of years.

Do not use the apostrophe to form the plural form of a numeral.

Correct: The first incandescent light bulb was invented by Thomas Edison in the late 1870s.

An apostrophe may precede a numeral expressing a decade, as in

Correct: The current decline in the housing market is often compared to the one in the '80s.

When the word o'clock is used, the word expressing time should be spelled out; otherwise, a.m., p.m. should be used with a numeral.

If neither o'clock or a.m./p.m. are used in the sentence, the time should be spelled out.

Correct: The meeting is scheduled at four in the afternoon.
Correct: The meeting is at 4:00 p.m.
Correct: We are meeting at two-thirty tomorrow.

Rule to Remember

Spell out time when no a.m. or p.m. is used.

Spell out simple fractions.

When the date includes month, day, and year, a comma should be used to set off the year. If only the month is used, no commas are needed.

Correct: Our first mortgage payment is due October 15, 2007.
Correct: Our first trip to Europe was in October 2006.

Simple fractions should be spelled out. A more complex fraction can be represented as a numeral unless it is at the beginning of the sentence.

Incorrect: 1/3 of our income goes toward the mortgage payment.
Correct: One-third of our income goes toward the mortgage payment.

With large numbers consistency and simplicity are very important.

Incorrect: Depending on the interest rate, your mortgage payment can be as low as five hundred or as high as $1,500.
Correct: Depending on the interest rate, your mortgage payment can be as low as $500 or as high as $1,500.
Correct: Depending on the interest rate, your mortgage payment can be as low as five hundred or as high as fifteen hundred.

Rule to Remember

Hyphenate compound numbers.

Use commas to separate thousands, millions, etc.

Compound numbers should be hyphenated.

Correct: They had twenty-five tickets available.

Commas should separate thousands, millions, etc. And a decimal point should be used with decimal numbers.

$1,200,000
$1,200.15


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