Step 1: Divide the number into separate digits:
2876 => 2 8 7 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 8 = 6
8 to 7 = 1
7 to 6 = 1
6 to 2 = 4
Step 3: Combine the filters to a string:
6 1 1 4 = 6114