Calculate the digit sum of 199
Calculate the reduced digit sum of 199
Digit Sum → 1 + 9 + 9 = 19
Since our digit sum > 9:
repeat this process to get the reduced digit sum:
Our new number to evaluate is 19
Digit Sum → 1 + 9 = 10
Since our digit sum > 9:
repeat this process to get the reduced digit sum:
Our new number to evaluate is 10
Digit Sum → 1 + 0 = 1
Since our digit sum ≤ 9:
we have our reduced digit sum