Step 1: Divide the number into separate digits:
24722 => 2 4 7 2 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 4 = 2
4 to 7 = 3
7 to 2 = 5
2 to 2 = 0
2 to 2 = 0
Step 3: Combine the filters to a string:
2 3 5 0 0 = 23500