1. The general rule is to spell numbers of one or two digits.
        Example: We’ll need two new printers to get the job done.
2. When you have a mixture of one-digit numbers and larger numbers, use numerals for all of them.
        Example: Of 230 traffic accidents this month, 90 involved alcohol and 62 were related to some other drug.
3. Spell a number if it starts a sentence. If the number is a year, you can either spell it or use numerals.
        Example: One hundred and ten seniors came to the picnic.
4. Spell fractions less than one.
        Example: About three-quarters of the investors lost money.
5. Use a numeral for percent, decimals, and fractions more than one.
        Example: Less than 70 percent of the citizens voted.
More than 30% of cabinet ministers lost their seat.
6. When two numbers are used in sequence, spell one number and use a numeral for the other.
        Example: Russell sold six 4-door sedans this week.
In business and technical writing, numbers are sometimes preferred to words. Your employer’s standard is your guide.