Step 1: Divide the number into separate digits:
94420 => 9 4 4 2 0
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
9 to 4 = 5
4 to 4 = 0
4 to 2 = 2
2 to 0 = 2
0 to 9 = 9
Step 3: Combine the filters to a string:
5 0 2 2 9 = 50229