This is one of two blog posts on fractions and ranges. This blog addresses how to draft fractions in a contract, part 2 will discuss ranges of numbers. For loyal followers of this blog, it is needless to say that the blog elaborates on the posts about drafting numbers (click here for the last one, which includes links to the related blogs).
I can see two best practice rules on drafting fractions on contracts (and other texts):
1) Avoid using fractions.
When fractions are used as adverbs or adjectives, insert hyphens. Do not insert hyphens if the fraction is a noun. In a closely linked phrase avoid combining fractions and words.
- a two-thirds increase
- increased by two thirds
- two-thirds completed, but not: ⅔ completed
Never contrast or compare a fraction with a decimal (i.e., avoid the applicable interest rate shall be 6¼ percent instead of 5.1 percent).
2) When used, fractions should always be spelled out in words, even when the figures are higher than ten, unless they relate to round numbers.
- The JVC shall budget one tenth to developing its distribution network, a twentieth to R&D and no more than a thirtieth to raw materials.
- 8½, 29¾
Fractions may be subject to the general drafting principle to ‘be accurate’: in many cases, fractions are more precise than decimals (e.g., 6.33 neglects the implied infinity of the fraction, which is embraced by 6⅓). Otherwise, prefer the use of fractions for rough figures (the JVC shall make best efforts to decrease production costs by 3½ percent a year) and decimals for more exact ones: The retail price index is rising at an annual rate of 10.6 percent.
Note that 2.5 (as in 2.5 percent) is not the same as 2.50 or 3½! Each decimal place, even if zero, adds to the accuracy. The non-decimal fraction is more approximate.