After the summer holidays, I thought it appropriate to take a dive into figures right away …
and below you will find the answer to a “number” of issues people have brought to my attention over the months.
When to Spell Out
In text material, cardinal numbers from zero through ten (some say twelve, this being a question of house style), should be expressed in words and those above ten in figures,
unless the number begins a sentence (all numbers should be spelled out when they begin a sentence) or unless they are listed below under “Always in figures”. Examples:
Approximately ten people were in the auditorium.
Enrolment in the graduate programme increased by 52 students.
Fifty-two people were in the auditorium.
In discussions in which clusters of spelled-out numbers would be cumbersome, use figures for all numbers.
The number of non-profit organisations in each city was as follows: Brussels, 7;
Antwerp, 8; and Ghent, 1.
Numbers in the same category within the same context should all be figures.
In one block a 103-story office building rises between two old apartment houses only 3 and 4 stories high.
Numbers used to express percentages should be written with numerals followed by the word percent (per cent). However, the percent sign (%) may be used in tables.
15 percent, 49 percent, 3 percent.
Units of Measurement
Physical quantities—weights, pressures, temperatures, distances, lengths, widths, areas, volumes, etc. should be expressed in figures.
2 metres, 3 kilos, 180 degrees.
In measurements of less than one, the unit of measurement should be expressed in the singular. If more than one, the unit of measurement should be expressed in the plural.
Index numbers and ratios should be expressed in figures.
price index of 121
1969 = 100
a 4:1 ratio.
Exact times should be expressed in figures, before a.m. (ante meridiem) and p.m. (post meridiem), with hours and minutes separated by a full stop (UK) or colon (US).
10.30 a.m. or 10:30 a.m. ten-thirty in the morning
12.00 p.m. or 12:00 p.m. twelve noon
12.00 a.m. or 12:00 a.m. twelve midnight
Fractions and decimals
Fractions should be spelled out in the text except for physical measurements, decimal fractions, and percentages.
More than three fourths (not three quarters).
In decimal amounts of less than one, a zero should be placed to the left of the decimal point.
EUR 0.5 billion, 0.7 percent.
Exact amounts of money should be expressed in figures. For large amounts in round numbers, use the word “million”, “billion”, or “trillion”, rather than zeros. The form is the same for singular and plural, e.g., EUR 1 million, GBP 1 billion. The currency abbreviation and the amount should never be separated at the end of a line.
This is a good start, but here are a few more guidelines.
So, NEVER begin a sentence with a numeral: either spell out the number, or rewrite the sentence to move the number away from the beginning.
Very large round numbers should be spelled out: not 1,000,000,000, but one billion. And this is the only time you should mix spelling and numerals.
In a series of numbers, either spell them out or use numerals for every member of the list: do not switch in the middle, as in "pages thirty-two, ninety-six, 107, and 235”.
There's no reason to use both numerals and words for the same number: unless a law firm is paying you enough money to butcher the language with impunity, steer clear of abominations like "two (2)" or “100 (one hundred)."
Use numerals for anything difficult to spell out: not four and sixteen seventeenths, thirteen thousand three hundred twenty six, or three point one four one five nine. You can however, spell out simple fractions like one half or two thirds.
Signs and signals with Figures
The signs +, -, :, %, °, €, and $ should be placed directly against the figure.
Always in figures
Age: 6 years old, aged 55
Dates: "3 October 2002”, “September 11, 2001”.
Degrees: 35°30’, -4°C
Market quotations: the bonds sold out at 95.
Page numbers: pages 19-26, pp. 34-35; 108-109.
Parts of written work: Chapter 2, Table 10, Section III.
Serial numbers: Document 310, pamphlet No. 26.
Votes: by a vote of 4 to 1 with 2 abstentions, yeas 25, nays 4.