Academic Skills Office (ASO) – Fact Sheets Page | 2
3. When to use digits for numbers
• Use digits for numbers greater than 10 and in the following situations
Use digits for Examples
Numbers 10 and
above both cardinal
and ordinal
For cardinal numbers (e.g., I counted 3,968 books).
For ordinal numbers (e.g., He was the 12
th
in line). Use either 12th or 12
th
but
be consistent.
Money
Use digits for exact amounts (e.g., $24.28), but use digits and words for
rounded and large amounts (e.g., 98 dollars; $15 million).
Measurements
Numbers that precede a unit of measurement (e.g., 32
0
C or 32 degrees
or
Percentages
Use 5% or 5 percent (e.g., Over 5% of students passed the examination.).
Fractions & decimals
Fractions: Write in digits or words. If you use words, join the fraction parts
with a hyphen (e.g. ⅔ or two-thirds).
Decimals: Give exact amounts in digits (e.g., 0.45 not .45; 2.36).
Surveys
Write survey results in digit form (e.g., A survey of participants revealed that 4
out of 5 students worked.).
Scores
Write scores in digit form (e.g., Students scored from 8 to 75 out of 100.).
Points on a scale (e.g., scored 3 on a 5-point scale)
Statistics
Use digits to describe statistical information (e.g., The survey focused on 90
teachers, 10 principals, and 24 auxiliary staff from 20 different schools.).
Eras & time spans
Use numbers for centuries (e.g., the 18
th
century or the 18th century).
Time spans (e.g., from the 1960s to the 1990s; during the 2000s; in 2300 BC
[before Christ]; in 1770 AD [anno Domini, after Christ]).
Date & time
Use this order (day/month/year) consistently (e.g., Tuesday 23 February 2008).
Choose from a variety of formats but be consistent (e.g., 9 am or 9.00 am or
8.22 pm or 4 o’clock).
Age
e.g., 2-year-olds, ages 5–7 years, was 6 years old.
Spans of numbers
Use digits (e.g., pages: 56–74, 115–117; years: 1864–1899, 1998–2008; streets
36–99 Spa St). Use an n dash for the span.
Specific place in a
numbered series if
placed 1after the noun
Divisions in books and plays (e.g., Volume 5, Chapter 6, page 45; Act 2, Scene
4).
School grades (e.g., Year 1, Grade 4)
Sequence of tables, figures, questions (e.g., Table 2, Figure 3, Question 1)
4. How to write numbers correctly
• Use particular conventions if you are required to write digits
a. In general, use commas between groups of three digits in numbers of 1,000 or more
(e.g., 1,360; 566,420; 10,235,362).
b. To create a plural, add an ‘s’ (e.g., 20s, 5s).
• Use particular conventions if you are required to write numbers in words
a. To create a plural, add ‘s’ or ‘es’ (e.g., twos, sixes).
b. Use hyphens for fractions and if necessary to write a two-digit number in words such as
at the beginning of a sentence (e.g., 94 = ninety-four; ⅜ = three-eighths).