Isn't that exactly the same thing as counting from 1000 to 9999 ?
It's 9999 numbers, minus the first 999 (they have less than 4 digits), which leaves 9,000 of them.
55----------------------------------------------------------------------------------------------From Rafaelrz.You can make, 5! = 120, five digit numbers using 1,2,3,4 and 6.
10999
24
You can make 4*3*2/2 = 12 numbers.
106------------------------------------------------------------------------------------------------From Rafaelrz.You can make, 4P3 = 4!/(4-3)! = 24, different 3 digit numbers using 1, 2, 3 and 4.
If you want 4-digit numbers, there are 24 of them.
3! = 6.
ccsndf
9
-5674
9999999999 100000000
8 of them.