The four digits can be used to produce infinitely many different numbers if repetition is permitted.
Without repetition, there are 24 possible numbers.
A lot more can be produced if the numbers are combined using binary oprations, fore example, 19 * 8/4 = 19*2 = 38.
4!=4x3x2x1=24
10+23 = 33
There are 360 of them.
9
210
Assuming you mean four different numbers, 0.123
2222
4!=4x3x2x1=24
If the digits are all different then 18. Otherwise, 192.
10+23 = 33
the least number is 210 which is divisible by four different prime numbers.
There are 360 of them.
24, if you permit numbers starting with 0, 18 otherwise.
9
210
8
They are the same. The rules of arithmetic do not change simply because you choose to represent the numbers differently.