The CAS Registry Mumber 98186-01-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,8,1,8 and 6 respectively; the second part has 2 digits, 0 and 1 respectively. Calculate Digit Verification of CAS Registry Number 98186-01: (7*9)+(6*8)+(5*1)+(4*8)+(3*6)+(2*0)+(1*1)=167 167 % 10 = 7 So 98186-01-7 is a valid CAS Registry Number.