1,956 different numbers can be made from 6 digits. You can calculate this by using the permutation function in a summation function, like this:
Σ6k=1 6Pk = 6P1+6P2+...+6P5+6P6
What this does is calculate how many 1 digit numbers you can make from 6 digits, then how many 2 digit numbers can be made from 6 digits and adds the amounts together, then calculates how many 3 digit numbers can be made and adds that on as well etc.
Including leading zeroes, the answer is 720. If you don't include leading zeroes, then 600.
6
5040
24680
To form a 4-digit number using the digits 2, 6, 9, and 5 without repeating any digit, you can use all four digits. The number of ways to arrange 4 digits is calculated as 4! (4 factorial), which equals 24. Therefore, you can form 24 different 4-digit numbers with the numerals 2695 without repeating any digit.
Including leading zeroes, the answer is 720. If you don't include leading zeroes, then 600.
6
5040
1,023,456,789
24680
9875.
9,876,543,210 9876543210
There are 840 4-digit combinations without repeating any digit in the combinations.
Assuming whole numbers and a leading zero does not count: 10,234,567
256
24
93876