Step 1: Divide the number into separate digits:
8769 => 8 7 6 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 7 = 1
7 to 6 = 1
6 to 9 = 3
9 to 8 = 1
Step 3: Combine the filters to a string:
1 1 3 1 = 1131