100
unless negative numbers are permitted: in which case, the answer is -999
1023456789
10234567
0123456789
10234567
Since there are only five different digits, a 6-digit number can only be generated if a digit can be repeated. If digits can be repeated, the smallest 6-digit number is 111111.
100,000,000,000
102
103
The smallest number with no digits repeated would either be zero or one, depending on the set of numbers you want to choose from.
The smallest 3 digit counting number less than 1000?? 100
1000000000 or, if negative numbers are permitted, then -9999999999
The first digit would have to be 1, the remaining digits, zero.