The CAS Registry Mumber 41192-99-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,1,1,9 and 2 respectively; the second part has 2 digits, 9 and 9 respectively. Calculate Digit Verification of CAS Registry Number 41192-99: (7*4)+(6*1)+(5*1)+(4*9)+(3*2)+(2*9)+(1*9)=108 108 % 10 = 8 So 41192-99-8 is a valid CAS Registry Number.