Here is the sixty-four thousand dollar ($64,000) question: Why do we repeat numbers?
I am talking about these redundancies:
within seven (7) days
fourteen dollars and seven cents ($14.07)
a waiting period of sixty (60) days
Answer: Because we have always done it that way!
Despite how we have always done it, there is only ONE situation in which it makes sense to render a number in both words and figures: when writing a check. On a check, we include a spelled out version of the amount to reduce the likelihood that anyone will misread the number or alter it.
We don’t need to restate a number in a typed business letter, memo, email, report, or even a contract.
You may be hesitant to stop writing numbers in both figures and words in your contracts. To encourage you to stop, I cite expert Bryan A. Garner, editor of Black’s Law Dictionary. In his book Legal Writing in Plain English: A Text With Exercises, Garner (who refers to the redundant numbers as "word-numeral doublets") states:
"There’s no good reason why modern briefs, judicial opinions, statutes, or contracts should contain doublets."
He provides this example of what not to do:
"The parties have agreed that for purposes of this Agreement, the current fair market value of the Property is Three Hundred Eighty-Nine Thousand Six Hundred Sixty-Seven and 00/100 dollars ($389.667.00)."
He replaces that bloated sentence with this concise wording:
"For purposes of this Agreement, the current fair market value of the Property is $389.667."
One argument often given for the doubled numbers is that they prevent discrepancies. But Garner refutes that reasoning:
" . . . discrepancies aren’t possible unless you write it twice."
Then why do so many people write numbers in words and figures? According to Garner, the use of "doublets" came about centuries ago to prevent number altering. And in the modern age, with the widespread use of carbon paper, numbers written in words were easier to decipher on carbon copies.
I hope you are convinced: These days it is unnecessary and downright silly to render a number two (2) different ways.
NOTE: The $64,000 Question was a television show in the US in the late 1950s. The name was written in figures–never spelled out!
For rules on writing numbers, see this post.