Chapter 3: One to nine and beyond: International Development Research Centre

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Chapter 3: One to nine and beyond

Document(s) 4 of 10

Numbers
Units
Temperature
Time
Statistics
Mathematics
Currencies

NUMBERS

For technical and scientific publications, the following rules must be applied. In more popular publications, style may vary according to the target readership. Alternatives are noted here.

General rule

Use words for numbers one through nine and numerals for larger numbers.

Examples: nine rabbits; two dogs; 14 parts; 29 trees

Exceptions
A numeral is always used:

With a standard unit of measure or its abbreviation.

Examples
3 hours; 1 g; 18 mm; 5%; 7 L
For a date, an expression of time (that is, hours, days, months, years), a page number, a percentage, a decimal quantity, or a numerical designation.

Examples
7 January 1971; the time is 0815 hours; page 179; 27%; 37.6 g; a magnification of 50.
In a series containing some numbers of 10 or more, and some less than 10, use numerals for all.

Example
The 7 apple trees, 9 peach trees, and 20 plum trees were given six applications of dust.
Note: The "six" is not part of the series.

Ordinal numbers

Treat ordinals as you would cardinal numbers.

Examples: third, ninth, 10th, 33rd, 54th

Numbers above 999

Numbers above 999 must be written with spaces, both in text and tabular material. It is useful to use a "hard space" (keyed <Home><Space> in WordPerfect) as this will hold the parts of the number together at the end of a line.

Examples: 1 500; 2 515 200; 0.000 001

Exceptions are years or pagination in a reference listing, where no space is used.

Examples: In 1992, IDRC was designated as an Agenda 21 organization.; Gove, P.B., ed. 1981. Webster's ... Springfield, MA, USA. 2662 pp.

Very large numbers
Substitute a word or a power of 10 for part of the number or add an appropriate prefix (Table 1) to a basic unit of measurement.

Examples: 23 mg, not 0.000 023 g; 5.5 billion people, not 5 500 000 000 people; in scientific publications, 2.9 × 10⁶ t is better than 2 900 000 t.

Table 1. SI prefixes.
Multiplying factor	Prefix	Symbol
1 000 000 000 000 = 10¹² 1 000 000 000 = 10⁹ 1 000 000 = 10⁶ 1 000 = 10³ 100 = 10² 10 = 10¹ 1 = 10⁰ 0.1 = 10^-1 0.01 = 10^-2 0.001 = 10^-3 0.000 001 = 10^-6	tera giga mega kilo hecto deca — deci centi milli micro	T (trillion)* G (billion)* M (million)* k h da — d c m µ
* For IDRC publications, use the million, billion, and trillion shown here. Note that British usage is 10⁶ = million; 10¹² = billion; 10¹⁸ = trillion.

Miscellaneous points

Abbreviations of units
Never abbreviate units of measure (see "Units") in the text without numbers. In tabular material, abbreviations may be used alone.

Adjectival units
Use hyphens in adjectives that contain numbers, but do not double hyphenate.

Example: a 16-ha field; a 30-page book; but; a 5 m high fence; a 5 cm diameter pipe.

Fractions
Hyphenate fractions when written out.

Example: One-third, four-fifths.

Leading zeros
Numbers below one always have a zero before the decimal in text and in tables.

Example: The crude mortality rate was 0.4 per 100 000.

Negative numbers
The minus sign in a negative number is not spaced from the numeral but it is spaced when it is a sign of mathematical operation.

Examples: -6°C but (x - y).

Numbers at start of sentence
Do not begin a sentence with a numeral; either spell out the numeral, reword the sentence, or end the preceding sentence with a semicolon.

Numbers with "-fold"
Numbers with -fold are solid with the base word except over nine.

Examples: threefold, ninefold but 10-fold, 25-fold.

Note: Follow the exceptions under "Numbers, General rule" at the beginning of this chapter with respect to a series of numbers.

Solidus (/)

Use only the solidus (slash) for per when reporting numbers in scientific text.

Example: Yields averaged 2.4 t/ha.

Exceptions

If several words come between the first and second parts of the expression.

Example
The field was seeded at 3 t/ha but The farmer used 3 t of seed per hectare.
If the "word" is an abbreviation, the solidus may still be used.

Example
"Fertilizer at 3 t of nitrogen per hectare" should be written as "... 3 t N/ha."
Solidus with % — Do not use the solidus after %.

Example
3.5% per year not 3.5%/year.
Solidus twice with one number — Do not use the solidus if it would occur twice with one number.

Example
Consumption was increasing at a rate of 3.5 kg/person per year.
In more popular "nonscientific" publications, use per or rework the sentence.

Examples
Consumption increased by 3.5 kilograms per person per year.
Annual consumption growth was 3.5 kilograms per person.

UNITS

Use SI units (Système International d'Unités) for measurements. If the book has many measurements in British units, give conversion factors to SI units so that the readers can make the conversions if they believe it is necessary. In scientific books, units are abbreviated. In more popular texts, all units should be written out in full.

Example: Use percent not %.

Conversions

Table 2. Key conversions.
Length
inch foot yard mile	= 2.540 cm = 0.3048 m = 0.914 m = 1.609 km	millimetre centimetre metre kilometre	= 0.039 inch = 0.394 inch = 3.281 feet = 0.621 mile
Area
square inch square foot square yard square mile acre	= 645.16 mm² = 929.0 cm² = 0.836 m² = 2.590 km² = 0.405 ha	cm² m² km² hectare	= 0.155 square inch = 1.196 square yard = 0.386 square mile = 2.471 acre
Volume (dry)
cubic inch cubic foot cubic yard bushel	= 16.387 cm³ = 0.028 m³ = 0.765 m³ = 36.369 L	cm³ m³ m³ hectolitre	= 0.061 cubic inch = 35.315 cubic feet = 1.308 cubic yard = 2.750 bu
Volume (liquid)
fluid ounce (Imp) pint (Imp) gallon (Imp)	= 28.413 mL = 0.568 L = 4.546 L	mL litre (L) litre	= 0.035 fl.oz = 35.196 fl.oz = 0.220 gal
Mass
ounce pound ton (2000 lb)	= 28.350 g = 0.454 kg = 0.907 t	gram kilogram tonne (t)	= 0.035 oz avdp = 2.205 lb avdp = 1.102 ton
Proportion
1 gallon/acre 1 pound/acre 1 pound/square inch 1 pound/square inch 1 bushel/acre	= 11.233 L/ha = 1.121 kg/ha = 0.070 kg/cm² = 6.895 kPa = 0.899 hL/ha	1 L/ha 1 kg/ha 1 kg/cm² 1 kilopascal 1 hL/ha	= 0.089 gal/acre = 0.892 lb/acre = 14.223 lb/square inch (psi) = 0.145 lb/square inch (psi) = 1.113 bu/acre
Energy
1 British thermal unit 1 kilowatt-hour	= 1.055 kJ = 3.600 MJ	1 kilojoule 1 megajoule	= 0.948 Btu = 0.278 kWh
Temperature
t degrees Fahrenheit t degrees Celsius	= 5(t - 32)/9°C = (9t/5) + 32°F

Be cautious of words based on a British unit of measure, for example, acreage and poundage.

Example: Not The acreage of a farm is 24 ha; but The area of the farm is 24 ha or The farm covers 24 ha.

Be cautious in converting materials that are standard sizes.

Example: A 3/16-inch bolt is not the same as a 4.7625-mm bolt — in the metric-sized bolts, there are probably 4.5- and 5-mm bolts but these would not necessarily fit in place of a 3/16-inch one.

Rounding numbers
When converting one type of unit to another in nontechnical work, round the converted value to within 5% of the original and use the word "about" or some other indication that the value is approximate.

Example: 5 lb or about 2.3 kg.

Be reasonable in the number of significant figures that you give; it should be the same as in the original. See the Canadian Metric Practice Guide (page 43) for rules on rounding numbers.

Example: An area of 1 000 acres is better reported as 404.7 ha (or maybe 405 or 400 ha depending on the context) not 404.686 ha.

SI (Système International d'Unités)

The degree to which the SI system is used in terms of abbreviations depends on the main target audience of the publication.

Scientific publications
Use SI abbreviations (including negative integers where appropriate). Give units in full if it is felt that the abbreviations would not be understood.

Example: Use year not "a" for annum.

Popular publications
For publications whose main target audience is a more general public, write out units in full.

Non-SI abbreviations
Do not use nonstandard abbreviations, rather use the full word.

Example: Use year not yr.

Canadian Metric Practice Guide
Table 3, which is adapted from the Canadian Metric Practice Guide (CAN3-Z234.1-89), shows both abbreviations and derivations of permissible units as well as names and symbols. When in doubt, consult the full guide.

Table 3. SI base units, derived units, and permitted units.
length mass time electric current thermodynamic temperature Celsius temperature amount of substance luminous intensity	metre kilogram second ampere kelvin degree Celsius mole candela	m kg s A K °C mol cd	- - - - - 1 K = 1°C - -
time	minute hour day year	min h d a	1 min = 60 s 1 h = 3 600 s 1 d = 86 000 s
plane angle	degree minute second revolution	#176; ' " r	1° = (pi/180) rad 1 r = 2(pi) rad
area	hectare	ha	1 ha = 10 000 m²
electric potential, potential defference, electromotive force	volt	V	m²-kg per s³ per A
volume	litre	L	1 L = 1 dm³
mass	metric tonne	t	1 t = 1000 kg = 1 Mg
frequency	hertz	Hz	per s
energy, work, quantity of heat	joule	J	m²-kg per s²

TEMPERATURE

If you must report temperatures in IDRC publications, always use the Celsius temperature scale (previously called Centigrade) — see Table 2 for conversion equation. Note the use of upper case C for Celsius, and that there is no space before or after the degree symbol.

Example: On 27 January 1993, the overnight low temperature in Ottawa was 18°C.

TIME

Years

Year ranges — Use an en dash.

Example: 1984–89.

Decades — Do not use an apostrophe.

Example: In the 1960s.

Noncalendar years — Use a solidus (/) not an en dash.

Example: The financial year 1979/80.

Dates

Use day month year — because the number-only system can lead to confusion, spell out the month.

Example: 16 September 1981.

Where months must be abbreviated, for example in tables or figures, use three-letter abbreviations — Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec — without periods.

Time of day

Use 24-hour system.

Example: 1630 hours.

However, if ante and post meridiem must be used, they should be AM and PM (note: no periods).

STATISTICS

Certain symbols in statistics are shown in italics, and others in Roman type. Table 4 shows the most common ones (from Scientific Style and Format, table 11.13).

Table 4. Statistical symbols.
Sample symbol Explanation
F
n
P
R
r
s
t
x Variance ratio (F-test)
Number of individuals or variates
Probability of wrongfully rejecting the null hypothesis (level of significance)
Coefficient of multiple correlation
Coefficient of correlation, sample
Standard deviation of the sample
Statistical datum derived in Student's t-test
Arithmetic mean of the sample

MATHEMATICS

Mathematics rarely appear in IDRC publications; if you have to deal with them, either consult the IDRC editor or see Mathematics in Type by the William Byrd Press (1954); Setting Mathematics by Arthur Phillips (1956); A Manual for Authors of Mathematical Papers by the American Mathematical Society (1962); or the Chicago Manual of Style.

CURRENCIES

When reporting currencies, use the International Organization for Standardization (ISO) codes for country names and currencies (ISO standards 3166 and 4217; see Table 5).

In scientific publications, ISO currency codes follow the currency values and are preceded by a space.

Example: 100 CAD

In more popular publications where a single currency is used throughout, the usual currency symbol may be used, provided that the currency is specified at its first mention in parentheses or as a footnote.

Example: $500 (US dollars throughout).

In more popular publications with a mixture of currencies, the usual currency symbol may be used with the ISO country code before the currency value (with a space).

Example: US $500.

A dollar value referred to in the text is assumed to be Canadian unless otherwise stated.

Give conversion rate to US dollars:

At first mention of a foreign currency in text:

Example
The wholesale price index of wheat rose from an average of 7 THB/kg in 1962 to an average of 18 THB/kg in 1978 (in 1985, 20 Thailand baht [THB] = 1 United States dollar [USD]).
In each table in which currencies are used, even if the exchange rate has already been given in the text, give the exchange rate as a footnote.

To get current values for exchange rates, phone the Royal Bank Information Centre (1-800-263-9191). They will give the foreign currency in terms of US dollars but you must ask specifically "how many ? currency equals 1 USD?"

Selected ISO country and currency codes

Spelling of country names follows the UN terminology bulletin for names of countries.

ISO country and currency codes are frequently updated — they can be checked by the IDRC Library through RADIUS.

Table 5. ISO country and currency codes.
Country Code Currency Code
Afghanistan
Algeria
Angola
Argentina
Australia AF
DZ
AO
AR
AU afghani
Algerian dinar
new kwanza
Argentine peso
Australian dollar AFA
DZD
AON
ARS
AUD
Bahamas
Bangladesh
Barbados
Benin
Bermuda
Bolivia
Botswana
Brazil
Burkina Faso BS
BD
BB
BJ
BM
BO
BW
BR
BF Bahamian dollar
taka
Barbados dollar
CFA franc BCEAO*
Bermudian dollar
Boliviano
pula
cruzeiro
CFA franc BCEAO* BSD
BDT
BBD
XOF
BMD
BOB
BWP
BRE
XOF
Cambodia
Cameroon
Canada
Central African Republic
Chad
Chile
China
Colombia
Congo
Costa Rica
Côte d'Ivoire KH
CM
CA
CF
TD
CL
CN
CO
CG
CR
CI riel
CFA franc BEAC**
Canadian dollar
CFA franc BEAC**
CFA franc BEAC**
Chilean peso
yuan renminbi
Colombian peso
CFA franc BEAC**
Costa Rican colon
CFA franc BCEAO* KHR
XAF
CAD
XAF
XAF
CLP
CNY
COP
XAF
CRC
XOF
Dominica
Dominican Republic DM
DO East Caribbean dollar
Dominican peso XCD
DOP
Ecuador
Egypt
El Salvador
Ethiopia
European Community EC
EG
SV
ET sucre
Egyptian pound
El Salvador colon
Ethiopian birr
European currency unit ECS
EGP
SVC
ETB
ECU
France FR French franc FRF
Gambia
Germany
Ghana
Guatemala GM
DE
GH
GT dalasi
deutsche mark
cedi
quetzal GMD
DEM
GHC
GTQ
Honduras
Hong Kong HN
HK lempira
Hong Kong dollar HNL
HKD
India
Indonesia
International Monetary Fund
Iran
Iraq IN
ID
IR
IQ Indian rupee
rupiah
Special Drawing Rights
Iranian rial
Iraqi dinar INR
IDR
XDR
IRR
IQD
Jamaica
Japan
Jordan JM
JP
JO Jamaican dollar
yen
Jordanian dinar JMD
JPY
JOD
Kenya
Korea, Democratic People's Republic of
Korea, Republic of KE
KP
KR Kenyan shilling
North Korean won
won KES
KPW
KPW
Lesotho
Liberia
Libyan Arab Jamahiriya LS
LR
LY loti
Liberian dollar
Libyan dollar LSL
LRD
LYD
Malawi
Malaysia
Mali
Mexico
Morocco
Mozambique
Myanmar MW
MY
ML
MX
MA
MZ
MM kwacha
Malaysia ringgit
CFA franc BCEAO*
Mexican nuevo peso
Moroccan dirham
metical
kyat MWK
MYR
XOF
MXN
MAD
MZM
MMK
Namibia
Nepal
Netherlands
New Zealand
Nicaragua
Niger
Nigeria NA
NP
NL
NZ
NI
NE
NG Namibian dollar
Nepalese rupee
Netherlands guilder
New Zealand dollar
cordoba oro
CFA franc BCEAO*
naira ZAR
NPR
NLG
NZD
NIO
XOF
NGN
Oman OM rial Omani OMR
Pakistan
Panama
Papua New Guinea
Paraguay
Peru
Philippines
Puerto Rico PK
PA
PG
PY
PE
PH
PR Pakistan rupee
balboa
kina
guarani
nuevo sol
Philippine peso
US dollar PKR
PAB
PGK
PYG
PEN
PHP
USD
Rwanda RW Rwanda franc RWF
Senegal
Sierra Leone
Singapore
Somalia
South Africa
Sri Lanka
Swaziland
Sweden
Switzerland SN
SL
SG
SO
ZA
LK
SZ
SE
CH CFA franc BCEAO*
leone
Singapore dollar
Somali shilling
rand
Sri Lanka rupee
lilangeni
Swedish krona
Swiss franc XOF
SLL
SGD
SOS
ZAR
LKR
SZL
SEK
CHF
Tanzania
Thailand
Trinidad and Tobago
Tunisia
Turkey TZ
TH
TT
TN
TR Tanzanian shilling
baht
Trinidad and Tobago dollar
Tunisian dinar
Turkish lira TZS
THB
TTD
TND
TRL
Uganda
United Arab Emirates
United Kingdom
United States
Uruguay UG
AE
GB
US
UY Uganda shilling
UAE dirham
pound sterling
US dollar
Uruguayo UGX
AED
GBP
USD
UYU
Viet Nam VN dong VND
Yemen YE Yemeni rial YER
Zaire
Zambia
Zimbabwe ZR
ZM
ZW zaire
kwacha
Zimbabwe dollar ZRZ
ZMK
ZWD
* CFA franc BCEAO: responsible authority — Banque Centrale des États de l'Afrique de l'Ouest.
** CFA franc BEAC: responsible authority — Banque des États de l'Afrique Centrale.

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