Step 1: Divide the number into separate digits:
0294 => 0 2 9 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 2 = 2
2 to 9 = 7
9 to 4 = 5
4 to 0 = 4
Step 3: Combine the filters to a string:
2 7 5 4 = 2754