Step 1: Divide the number into separate digits:
9466 => 9 4 6 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
9 to 4 = 5
4 to 6 = 2
6 to 6 = 0
6 to 9 = 3
Step 3: Combine the filters to a string:
5 2 0 3 = 5203