Some simple ideas about numbers.
Numbers come in three categories:
Cardinal numbers indicate how many. These are the numbers we’re most used to. They show quantity:
1. The system has six butterfly valves
2. They made twelve payments
3. The signal repeated 12 times.
In business writing, spell out numbers less than one hundred (examples one and two). In technical writing, spell out numbers less than ten (example three). Technical writing uses numbers more; using numerals make them “pop.”
Ordinal numbers indicate sequence. First. Second. Third. They show rank or position. Think of the items lined up in order:
1. She placed second in the writing competition.
2. The restaurant’s on the twelfth floor.
3. The 12th sample tested positive for halocyne.
Follow the same guidelines for spelling the numbers out: less than one hundred in business writing (examples one and two). Less than ten in technical writing (example three).
We suggest—and The Chicago Manual of Style suggests—the letters not appear as superscripts (for example, you shoud write 12th instead of 12th), but you may have to fight your word-processing program with this.
Nominal numbers name something. They identify something. They show neither quantity nor rank:
1. Babe Ruth wore number three on his jersey.
2. TelCo’s headquarters is in zip code 84101.
3. Route 107 runs from Edgeware to New Barnet.
Again, spell out numbers less than a hundred in business writing; spell out numbers less than ten in technical writing.
If you have questions, let us know. We love this stuff. Thank you for reading.