Step 1: Divide the number into separate digits:
2724 => 2 7 2 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 7 = 5
7 to 2 = 5
2 to 4 = 2
4 to 2 = 2
Step 3: Combine the filters to a string:
5 5 2 2 = 5522