Step 1: Divide the number into separate digits:
0302 => 0 3 0 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 3 = 3
3 to 0 = 3
0 to 2 = 2
2 to 0 = 2
Step 3: Combine the filters to a string:
3 3 2 2 = 3322