Step 1: Divide the number into separate digits:
0486 => 0 4 8 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 4 = 4
4 to 8 = 4
8 to 6 = 2
6 to 0 = 6
Step 3: Combine the filters to a string:
4 4 2 6 = 4426