The Language of Approximation

In report writing it is good style to use 'approximation' in the Findings, Conclusions and Recommendations. Approximation means describing numbers or statistics by using a fraction that is similar to the exact number; e.g. using 'about one-third' instead of 34.76%, or an easy-to-remember number such as 'just under one million' instead of '997,652'.

There are a number of reasons for doing this. Firstly, it is easier for people to understand and remember. Secondly, the numbers or statistics may be more detailed than necessary.

Here are some examples:

65% about two-thirds of   1,043 over a thousand
28% just over a quarter of 115 over a hundred
21% about a fifth 9 fewer than ten
49% just under a half of 2 a small number
74% almost three-quarters of 4 a few
33.3333% a third of 6 several
92% most of 749,982 about three-quarters of a million
98.5% almost all 1,256,890,534 over 1.2 billion


  • don't use fractions where the denominator (the number under the line) is greater than 5 - many people do not know that 1/6 = 16% or that  7/8 = 87.5%
  • don't forget the hyphen in fractions; e.g. 'one-third' (but not after 'a'; e.g. use 'a third')
  • don't forget to add an 's' on the end of fractions starting with two or greater; e.g. 'two-thirds', 'three-quarters'
  • most fractions can be followed by the preposition 'of '; e.g. 'Three-quarters of the staff were satisfied with working conditions.'
  • most fractions are followed by a plural noun; e.g. 'half of the books', except uncountable nouns; e.g. 'Half of the staff were satisfied with working conditions' (the verb is 'were', not 'was', because 'staff ' is thought of as a plural after fractions)
  • in strictly correct grammar use 'fewer than' for countable nouns and 'less than' for uncountable nouns
  • it is more natural to use 'a' instead of 'one' in front of fractions; e.g. 'a third of ...'
  • in front of 'half ' you do not need to use 'a' or 'one-'; e.g. 'Half of the staff were satisfied with their working relationships.'
  • do not use a number at the start of a sentence, because it's bad style. Use words; e.g. '100 One hundred of the staff were satisfied with working conditions.'
  • be careful of the spelling of 'several' - it's not 'serveral'
  • remember that 'only' and 'just' often have a negative meanings, so use them only if you want to show that something is bad; e.g. 'Only 1% of our staff were satisfied with working conditions.'

Match the items in the boxes on the left with the items on the right:

  1. Click in the table cell containing the item you want to move.
  2. Click in the table cell where you want the item to go. The words will swap position.
  3. If an item is in the right position, it will have a green background and a tick.
  4. When all the table cells are green and have ticks, you have finished.

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Last updated on: Monday, March 26, 2012