Numbers, measurements, dates and times

Expandable List

  • Spell out numbers from one to nine.
  • Use figures for 10 and above: 10, 11, 12, 13, 14, and so on.
  • Exception: Spell out the number if it begins a sentence: “Forty people replied.”
  • This rule also applies to ordinal numbers:
  • first, not 1st
  • 20th, not twentieth, unless in an official title
  • Don’t use superscript, even if Word wants you to:
  • NO: We’re aiming for 21st-century usage in our new editorial style guide.
  • YES: We’re aiming for 21st-century usage in our new editorial style guide.
  • Use figures for school grades, with a capital G on “Grade”:
  • Students start thinking about university in Grade 9.
  • Use figures in ages standing alone after a name:
  • Dr. Smith has a daughter, Jessica, 5.
  • Note that Level designations take Roman numbers:
  • The student is in Level III.
  • However, note that common usage is: first year, second year, third year, fourth year.
  • 20-something, 30-something
  • ‘60s Scoop:
  • Note the apostrophe [’] which indicates there are missing numbers.
  • Don’t use a single quotation mark.
  • Preferred usage: Sixties Scoop.
  • No. 1:
  • He’s always been my No. 1 fan.
  • Per cent:
  • Not percent.
  • But: percentage [no space].
  • Use the symbol % only in charts and tables.
  • Phase 1 [drug trials, etc.]
  • Phone numbers:
  • Use hyphens: 905-525-9140
  • Spell out terms such as pound(s), square feet (foot), metre(s), inch(es).
  • Metric symbols:
  • Metric symbols are not abbreviations; they never take “s” in the plural; they are separated from a number by a space; and they do not take periods except at the end of a sentence.
  • The names of metric units are usually spelled out: a 20-kilogram sack, not a 20-kg sack; covering 50 hectares, not covering 50 ha; ran 10 kilometres, not ran 10 km.
  • C (for Celsius) can be used on first reference:
  • With temperatures expected to drop below -15C overnight, social workers are calling for better housing measures.
  • Money:
  • No .00 with even dollars:
  • Tickets are $15 at the door.
  • When using the dollar sign, don’t use the word dollars:
  • NO: The government will give McMaster $5 million dollars.
  • YES: The government will give McMaster $5 million.
  • C for Canadian currency, if you need to differentiate that:
  • C$500
  • US for American currency:
  • US$295
  • Use “U.S.” to refer to the country.]
  • 21st century / 20th century
  • No superscript.
  • Use a hyphen if an adjective: 21st-century; 20th-century.
  • 1920–21, but: 1999–2003
  • 1930s, ’30s
  • Note the apostrophe [’] which indicates there are missing numbers.
  • Don’t use a single quotation mark.
  • Note there is no apostrophe before “s” to denote the plural.
  • Exceptions: Expo 67, Expo 86 [no apostrophes].
  • Abbreviate only: Jan., Feb., Aug., Sept., Oct., Nov. and Dec.
  • Do not abbreviate: March, April, May, June, July.
  • Spell out the month when standing with a year alone:
  • Convocation was held Nov. 17, 2006.
  • The Peace Camp lasted through January 1991 [no comma].
  • No st, nd, rd, or th on numbers in dates:
  • Jan. 1, not Jan. 1st
  • March 3, not March 3rd
  • Time is written in figures: 8:45 a.m., 9:30 p.m.
  • Exception: Write noon or midnight, not 12 noon or 12 midnight.
  • No :00 for exact hours:
  • The service will begin at 11 a.m.
  • a.m. and p.m.
  • Use periods after each letter; no space between.
  • Use lowercase.
  • No need to say “in the morning” after a.m. or “in the afternoon” after p.m.