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Fractions, Decimals, and Money

Rule: Always spell out simple fractions and use hyphens with them.

Example: One-half of the pies have been eaten.

Rule: A mixed fraction can be expressed in figures unless it is the first word of a sentence.

Example: We expect a 5 1/2 percent wage increase.
Example: Five and one-half percent was the maximum allowable interest.

Rule: Hyphenate all compound numbers from twenty-one through ninety-nine.

Example: Forty-three people were injured in the train wreck.

Rule: Replace a decimal point with and when you write out amounts on a check. You may use numerals in fraction form for cents.

Example: Fifty-two and 46/100 (“Dollars” will already be printed at the end of the line.)

Rule: Express large numbers simply. Be careful to be consistent within a sentence.

Correct: You can earn from one million to five million dollars.
Incorrect: You can earn from one million to $5,000,000.
Correct: You can earn from $500 to $5,000,000.
Correct: You can earn from five hundred dollars to five million dollars.
Incorrect: You can earn from $500 to five million dollars.

Rule: Write decimals in figures. Place a zero in front of a decimal as a courtesy to the reader.

Example: The plant grew 0.79 of a foot in one year.
Example: The plant grew only 0.07 of a foot this year because of the drought.

 

Pop Quiz: Correct or incorrect?

1. Eighty one people were injured in the train accident.
2. I wrote a check for $300, not $3,000.00.
3. Hair grows one fourth of an inch per month.
4. The tree grew .95 of a foot because of a wet winter.

 

Pop Quiz Answers: All sentences were incorrect.

1. Eighty-one
2. $3,000 (no .00)
3. one-fourth
4. 0.95

Posted on Sunday, August 24, 2008, at 11:22 pm


20 Comments

20 Responses to “Fractions, Decimals, and Money”

  1. Brandi Bergheimer says:

    I was wondering if it was supposed to be five and a half or five and a half? I remember that there was some funky rule about ‘A’ verses “AN” in this type of setting. Please help. Thank you Brandi

  2. Tristan says:

    I was wondering if there are any rules regarding where the dollar sign should go when using parenthesis to display a negative number. Is it $(500) or ($500)? The “Accounting” format in excel would display it as: $(500). Is that correct? Are both acceptable?

    • Jane says:

      The use of parentheses to indicate a negative number is typically seen on spreadsheets, not in formal writing, to which my rules apply. Rule 1 in the Parentheses section of GrammarBook.com says, “Use parentheses to enclose words or figures that clarify or are used as an aside.” Thus, in formal writing, parentheses would not indicate a negative number.

      Example: I expect five hundred dollars ($500).

      In most formal writing, use the minus sign to indicate a negative number.
      Example: -$500

  3. Bill says:

    Dear Jane,

    Isn’t it “one-million to five-million dollars?” Aren’t one- and five-million compound adjectival modifiers?

    Thanks,
    Bill

    • Jane says:

      As described in our blog “Numbers as Adjectives,” you would hyphenate when a number and a measurement unit taken together form an adjective, that is, when they describe another object. An example would be “a five-million-dollar deficit.”

      • Bill says:

        Doesn’t my previous point stand? To use your example — five-million-dollar deficit — isn’t it equally appropriate to hyphenate, e.g., five-dollar deficit? Therefore, my original example, ” one-million to five-million dollars,” (originally yours without hyphens) stands, and, in fact, would be better expressed thusly: “one- to five-million dollars.” ??

        Thanks. Lots of fun.

        • Jane says:

          Grammatically speaking, there is no difference between five million dollars, 12 hours, 25 yards, four pounds, etc. They are simply numbers with their unit definitions. The important phrases from the “Numbers As Adjectives” blog that I used below is, “hyphenate when a number and a measurement unit taken together form an adjective, that is, when they describe another object.”

          Notice the difference between:
          five million dollars vs. five-million-dollar deficit (or five-dollar deficit, quantity doesn’t matter)
          12 hours vs. a 12-hour shift
          25 yards vs. a 25-yard lead
          four pounds vs. a four-pound hammer

          Similarly, in expressing a range:
          Next year, we expect our deficit to range from one to five million dollars. vs. Next year, we expect a one- to five-million-dollar deficit.

          • Bill says:

            I submit that the phrases “four-pound hammer” and “five-million dollars” are identical: the noun in each case is modified by a compound adjectival modifier, thus requiring the hyphen in each case.

            If the two phrases differ, it is not a structural or contextual difference. Wherein, then, the difference? What am I not seeing?

            This is great fun.

            Bill

            P.S.

            “Grammatically speaking, there is no difference between five million dollars, 12 hours, 25 yards, four pounds, etc.”

            Au contraire. The difference between, e.g., “five million dollars” and “12 hours” is precisely grammatical: “12,” in the latter observation, is a simple adjectival modifier; “five million” is a compound modifier, thus requiring a hyphen.

          • Jane says:

            What you are not seeing is that four-pound hammer and five million dollars are not identical. Four is a number, five million is a number. Just because it takes two words to express the number five million, does not make it a compound adjective. Our blogs “Hyphens with Numbers” and “Numbers as Adjectives” explain this in more detail. I recommend that you read those blogs carefully along with the comments. The rule says, “When you are combining two or more words to form a compound adjective in front of a noun, put hyphens between these words.” The two words “four-pound” form a compound adjective in front of the noun “hammer.” The two words “five million” in front of dollars do not form a compound adjective. They simply form a number, a single adjective in front of dollars.

  4. Stefanie says:

    In the Grammar books I use, the rule for fractions states that when the fraction is being used as an adjective, you hyphenate it. (Ex. Two-thirds majority won the vote.)
    When you use the fraction as a noun, you don’t use the hyphen. (Ex. Two thirds of the pie was eaten. Two thirds here is the subject and therefore gets no hyphen.)

    • Jane says:

      The style manuals that we consulted do not agree with you. The Chicago Manual of Style’s rule (9.14) says, “Simple fractions are spelled out. For the sake of readability and to lend an appearance of consistency, they are hyphenated in noun, adjective, and adverb forms. In the rare event that individual parts of a quantity are emphasized, however, as in the last example, the fraction is spelled open.”

      She has read three-fourths of the book.
      Four-fifths of the students are boycotting the class.
      I do not want all of your material; two-thirds is quite enough.
      A two-thirds majority is required.
      but
      We divided the cake into four quarters; I took three quarters, and my brother one.

      Also, The Associated Press Stylebook says, “Spell out amounts less than 1 . . ., using hyphens between the words: two-thirds, four-fifths, seven-sixteenths, etc.”

  5. Ha Nguyen says:

    Dear Jane,
    I am studying a fraction and I ask you how to use a fraction
    For example,
    1) 3/4 of an egg is ripe. Is it right ?
    (I am wondering 3/4 of + N, N may be countable or uncountable) and N must be definite ?
    2) How to use percent is the same way as such 3/4

    Thank you in advance.

    • Jane says:

      A fraction or percentage is normally used with a countable noun. An egg cannot be ripe nor can it be easily divided into three quarters (unless it’s hard boiled). I have never seen a recipe that calls for a fraction of an egg. You could say 3/4 cup of egg whites, 3/4 of the eggs are brown, or 75% of the eggs are brown.

  6. Lynn Weston says:

    Is it correct to use fractions with metric units and vice versa? Ex: 205.5 pounds or 1/2 cm Thanks.

    • Jane says:

      It is correct to use decimals with metric units, but not fractions. Fractions are acceptable in the United States customary unit system, however, if you are including conversions you should be consistent and use only decimals. Examples:
      .5 cm
      72.5 kg
      2 1/2 lbs. OR 2.5 lbs.
      5 1/2 ft. OR 5.5 ft.

  7. Paula Barnett says:

    How would I write “A $30 dollar donation is requested.” Is that correct or should I write out thirty? Also, is there a hyphen between $30 and dollar since it’s modifying donation?

    • Jane says:

      The dollar sign ($) indicates “dollar.” We do recommend a hyphen in the spelled-out version, since it is a compound adjective.
      A $30 donation is requested. OR
      A thirty-dollar donation is requested.

  8. cindy says:

    How would I write $4,200,000? Do I round down? Any assistance would be greatly appreciated.

    • Jane says:

      The simplest way to express large numbers is usually best. We recommend writing the number as you have written it. Or you could use Associated Press style, which would write it “$4.2 million.”

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