Computers have no sense of style. When a number is less than ten, it is commonly written out rather than being presented in figures, except when speaking of a set of numbers where the higher number is greater than ten.
For example, when giving a street address one would write Three Main Street rather than 3 Main Street, or 142 Model Road rather than One Hundred Forty-Two Model Road. But if we were to give a set of addresses, such as 3 Main Street, 142 Model Road, and 1600 Example Avenue, one would use numerals for each, as the higher numbers are greater than ten.
But computers have no sense of style, and so you can confuse them by providing the word rather than the numeral.