People often have trouble deciding whether a number should be written numerically or spelled out. If that’s you or you have troubles knowing when to add a hyphen, there are some basic rules to follow.


Use numerals for:

  1. addresses- Do you have any clue what 221b Baker Street, London is known for?
  2. dates and times- I was born December 29, 1978 at 3:25 a.m.;
  3. decimals- try eating 3.14 slices of pi;
  4. measurements- the average person weighs 17 lbs (7.7) more than their ideal weight;
  5. money- a decent haircut in the West costs at least $30, not including tip;
  6. temperature- the coldest temperature recorded in North America is 81.4 F (-63 C);
  7. scores- The LA Lakers won their game against the Knicks 106-101;
  8. statistics- Nearly 51% of all people have experienced PMS.

Additional Rules

    • Write the word rather than the numeral if it comes at the beginning of a sentence: One-fourth of South Korea’s population lives in Seoul. Use hyphens to separate fractions.
    • Add a comma after every three digits. McDonald’s has served more than 100,000,000,000 hamburgers to customers all over the world.
    • You may shorten larger numbers such as million (M) or billion (B) with an initial. Whether you have $1M or $1B, you’ll still be able to buy ice cream for everyone.
    • If a number is smaller than one, use a zero before the decimal. My stock finally went up by 0.03% today.
    • Use –s without the apostrophe for plural numbers. AIDS became a global concern during the ’80s and ’90s.