Step 1: Divide the number into separate digits:
8826 => 8 8 2 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 8 = 0
8 to 2 = 6
2 to 6 = 4
6 to 8 = 2
Step 3: Combine the filters to a string:
0 6 4 2 = 0642