• Numbers zero through nine are spelled out.
• When a number begins a sentence, it’s always spelled out.
• If a number beginning a sentence is followed by another number of the same category, spell out only the first number, or reword.

• Ex:  “One hundred eighty of the 214 candidates had law degrees; the remaining 34 were doctoral candidates.”

• Simple fractions are spelled out.  For the sake of readability and to lend an appearance of consistency, they are hyphenated in noun, adjective, and adverb forms.

• Ex:  “She has read three-fourths of the book.”

• Quantities consisting of whole numbers and simple fractions may be spelled out if short but are often better expressed in numerals.

• Ex:  1¾

• Except at the beginning of a sentence, percentages are usually expressed in numerals.  In nontechnical contexts, the word percent is generally used; in scientific and statistical copy, the symbol % is more common.

• Spell out both, or use a number and the percent (%) symbol.

• No superscript for rd/th with numbers (3rd — not 3^rd)
• One-and-a-half-year-old son
• Three and a half years
• 50/50 — not 50%/50%
• Use an apostrophe when referring to a decade

• Ex.  The ‘90s

Dates

The following styles should be used when writing dates:  

• Day of the week, month day, year:  Tuesday, May 16, 2017
• Month day, year:  May 16, 2017
• Month, year:  May, 2017