The CAS Registry Mumber 98190-30-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,8,1,9 and 0 respectively; the second part has 2 digits, 3 and 0 respectively. Calculate Digit Verification of CAS Registry Number 98190-30: (7*9)+(6*8)+(5*1)+(4*9)+(3*0)+(2*3)+(1*0)=158 158 % 10 = 8 So 98190-30-8 is a valid CAS Registry Number.