Why is it important to use style guides?

It can appear sloppy and confusing if consistency is not applied to commonly used terms. For numbers, it is generally recognised that the numbers 0-9 should be represented by words, and for numbers after nine the layout may depend on the style guide. There is also a normalization rule that can be applied in some styles.

Using numbers, for example:

• The distance to Canterbury from Whitstable is six miles.
  [Apply the general rule]
• The distance to Canterbury from Whitstable is 6 miles, making it a round trip of 12 miles.
  [If the numbers appear in the same sentence and one is greater than nine and the other is not, most style guides would recommend that you normalize]
• Five men cycled 12 miles, of which 2 miles were in heavy traffic, on the second day of their round Kent trip.
  [Only normalize items which refer to the same thing e.g. miles in this case]
• Five men cycled to Whitstable. The 5 six-footers arrived on the seafront before sunset.
  [Adjacent numbers can look confusing e.g. the five six-footers, so some style guides recommend readability over consistency]
• Twenty children are in Year Two.
  [Numbers at the beginning of a sentence should be written out in full, however, for very long numbers you might want to consider re-writing your sentence e.g. There are 750 pupils in the school instead of Seven-hundred and fifty pupils attend the school]
• Five percent of cyclists wear black shorts.
  [Numbers at the beginning of the sentence rule]
• Black shorts are worn by 5% of cyclists.
  [Percentages even below 0-9 should be represented as numbers]

Time can be equally problematic for writers – six am, six a.m., 6AM, 6 am, 6.00, 06:00, six o’clock in the morning, 6 o’clock – and that’s before you even think about 6.30, half past six, GMT etc. That’s why it’s important to consult a guide before you start working on a thesis and understand the ground rules before too many errors appear in your final document.

Note: You must check the style guide for your discipline as rules may vary.