Write decimals in figures. Put a zero in front of a decimal unless the decimal itself begins with a zero.
Examples: The plant grew 0.79 of a foot in one year.
The plant grew only .07 of a foot this year because of the drought.
With numbers that have decimal points, use a comma only when the number has five or more digits before the decimal point. Place the comma in front of the third digit to the left of the decimal point. When writing out such numbers, use the comma where it would appear in the figure format. Use the word and where the decimal point appears in the figure format.
$15,768.13: Fifteen thousand, seven hundred sixty-eight dollars and thirteen cents
$1054.21: One thousand fifty-four dollars and twenty-one cents
Note: If the number has no decimal point, authorities disagree on whether to begin using the comma with four-digit numbers or to begin using the comma with five-digit numbers. When writing out these numbers, I recommend using the comma where it appears in the numerical form.
1,054 schools OR 1054 schools: one thousand, fifty-four schools OR one thousand fifty-four schools
12,154 schools: twelve thousand, one hundred fifty-four schools