Ok. I wonder if someone could help me with this problem... I want to calculate the number of digits of a positive integer. I was thinking of ... numDigits n = truncate (logBase 10 n) + 1 But (logBase 10 1000) = 2.9999999999999996 so numDigits 1000 = 2. Maybe adding a small amount numDigits n = truncate ((logBase 10 n) + 0.0000000000000005) + 1 Prelude> numDigits 100 3 Prelude> numDigits 1000 4 Prelude> numDigits 10000 5 Prelude> numDigits 10000 5 Prelude> numDigits 100000 6 Prelude> numDigits 1000000 7 Prelude> numDigits 10000000 8 Prelude> numDigits 100000000 9 Prelude> numDigits 1000000000 9 <---- This is wrong!!!! Prelude> numDigits 10000000000 11 Is there a reliable way to calculate the number of digits by means of logBase? Regards!