Using Numbers in AP Style

Need a refresher on how to use numbers on your webpages? The following examples will help you use numbers according to AP Style, the guide used for all NIU communications.

The No. 1 Rule

The main rule to remember is to spell out one through nine and use figures for 10 and above.


  • She’s taking four classes.
  • He studies 12 hours a week.
  • The number of students in the class ranges from nine to 15.


  • Ages (He is 9 years old.)
  • Units of measure (She is 5 feet, 5 inches tall.)
  • A number starting a sentence (Spell it out: Twenty people attended the lecture.)

Ordinal Numbers and Rankings

Ordinal numbers indicate order. Spell out first through ninth and use figures for 10 and above.

To indicate a ranking, use “No.” followed by the ranking as a figure.


  • She was first in line.
  • He’s in 10th grade.
  • We have the No. 1 program in the state.

Styles for Other Numbers

  • Phone numbers: 815-753-1234
  • GPA: 3.50 (Carry the decimal to two digits.)
  • Amounts of money: $20 (Don’t include the “.00” unless the figure is aligned in a table with other figures.)



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