Numbers in Chicago Format


When writing a nontechnical or a technical paper or essay, there is a high tendency of having to make use of numbers in your text, most especially if you are writing a scientific paper where you would have to report numerical information about your research.

Most authors are fond of spelling out the numbers that can be written in one or two words and then using figures for numbers that would require more than two words to be spelt out. However, the writing format for your paper or essay is what determine how numbers should be written in your text.

Therefore, if you are writing your paper or essay using the Chicago format, the manual states that for technical writing, the simple rule of spelling out only single-digit numbers and using numerals for all others should be followed. However, there are exceptions to this rule, and these exceptions are what we are going to be looking at in this article.

Formatting numbers in Chicago style

pointing hand Numbers to Be Spelt out

The following are exceptions where even if the number is more than nine it should be spelt out

  • Numbers That Begin a Sentence

Numbers should always be spelt out when they begin a sentence. This is done to avoid awkwardness. Even if a year has to begin the sentence, it has to be spent out in full.

For example

305 candidates failed the test

Twenty-twenty has been a horrible year so far.

  • Fractions

Simple fractions are meant to be spelt out for the sake of readability.

For example

Only about one-third of the students passed the exam

pointing hand Numbers to Be Written in Figures

The following are exceptions where even if the number is between zero to nine it should be written in figures

  • Ordinals

Ordinals should always be written in figures

For example

She found herself on the 9th floor

  • Units of measurement

When you are writing a number succeeded by a unit of measurement, the number should be written in figures.

For example


340 cm

  • Mixed fraction

Unlike simple fractions when a number is to be written along with a fraction, it should be written in figures

For example

You will need about 5½ yards of the cloth

  • Percentages

Percentages should be written in figures except when they appear at the beginning of the sentence.

For example

There is a 70% chance of winning with the right strategy

Seventy percent of people that were invited came

  • Decimal

Decimals should be written in figures, and when a quantity is less than 1.00, a zero should be kept before the decimal point.

For example

The students had a mean score of 45.3

It was in the ratio 0.62

  • Currency

Currencies and monies should be written in figures except it is an isolated reference to the amount of money

For example

500 dollars

230 pounds

  • Date

Cardinal numbers are used when writing a date. They should also always be written in the month-day-year date form or the day-month-year form

For example

May 2, 2020

11 January 1997

  • Time 

Time should be represented with numerals except for the approximation of time where you write them in words

For example

The time is exactly 10:50 pm

She was told to come by 8: am

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By Andy Xavier

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