What is the term for following a number, ie: ten (10) with the numeric version for clarity

Question

I see this a fair bit in journal papers, and wanted to know if there is a specific reason and/or term for this: having the spelled/lexical version of a number followed by the literal/logical representation. An example would be:

A fifty (50) caliber round can penetrate conventional armor.

Why is "fifty" trailed by "50", and what is the purpose? I can imagine this in translation documents or multilingual documents, but I'm confused why this is common practise in various papers, instruction manuals, etc.

Thanks!

Answer 1

Here is what Grammar Girl has to say about it:

Numbers in Parentheses

"Don't put numbers in parentheses after words."

By

Mignon Fogarty, Grammar Girl

July 23, 2015

Two readers recently asked whether they need to repeat a number in parentheses after they write out the word.

Note that I did not write two (2) readers.

Putting the number in parentheses after the word is unnecessary and no style guide that I'm aware of calls for it. It has a sense of legalese to it, but from what I can tell, it's not even required in legal writing anymore. Garner's Modern American Usage says it was originally done in legal writing to prevent fraudulent alterations. I guess if you had to alter both the word and the numeral, it would be harder than if you had to alter just one or the other.

That’s why you sometimes see a numeral in parentheses after a number that is written out—it is a relic of legal writing, but it’s not something you need to include in your writing today.

Answer 2

The parentheses are intended to make the number easier to find for later reference.

Technical writing has many guidelines, for good reasons, that would, also for good reasons, be considered violations in general writing.