Numerical References

As a general rule, write out numbers from one to nine; numbers 10 and over should be left in numerical form. Use commas in numbers higher than 999. Use numerals, however, when referring to sections of a book, units, grade point averages, ages, percentages and scores:

"See page 6 … A GPA of 3.0 … A total of 5 percent … Also, 9 units must be taken in residence at Fresno State."

When referring to percentages, do not use % except in tables and technical text:
More than 20 percent passed the test with a score of 85 or better.

Spell out ordinal numbers first through ninth. Numbers above the 10th ordinal may use figures: First, second, 10th, 23rd, 31st.

Academic years

Academic years should be written 2009-10.

Centuries

Use lowercase, spelling out numbers less than 10: the first century, the 21st century.

Decimals with numbers

Express grade point averages as 2.5, 4.0, etc.

Time of day

Use 8 a.m., not 8:00 a.m. Use noon or midnight and do not put a 12 in front of a.m. or p.m.

Years

Under most circumstances, use figures: "2009." Use an "s" without an apostrophe to indicate spans of decades or centuries: "Plan for the '90s, the 1990s, the Roaring '20s."