Spell out numbers under 10 (one through nine).
Use figures for numbers 10 and up.
Spell out a numeral at the beginning of a sentence.
Do not spell out numerals that identify a calendar year.
Decimals should not exceed two places in textual references, except for in special circumstances.
Be consistent with the number of decimal places used—if one number has two decimal places, all numbers should have two decimal places (2.25, 2.50, etc.).
Use figures with million or billion in all uses.
Always use numerals when referencing percentages.
Spell out percent unless it is included on a quick-reference list.