Step 1: Divide the number into separate digits:
4078 => 4 0 7 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 0 = 4
0 to 7 = 7
7 to 8 = 1
8 to 4 = 4
Step 3: Combine the filters to a string:
4 7 1 4 = 4714