Step 1: Divide the number into separate digits:
8926 => 8 9 2 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 9 = 1
9 to 2 = 7
2 to 6 = 4
6 to 8 = 2
Step 3: Combine the filters to a string:
1 7 4 2 = 1742