How many 3-digit numbers are there when a digit may be repeated any number of times?

How many 3-digit numbers are there when a digit may be repeated any number of times?
How many 3-digit numbers are there when a digit may be repeated any number of times?
How many 3-digit numbers are there when a digit may be repeated any number of times?
How many 3-digit numbers are there when a digit may be repeated any number of times?

times?