The CAS Registry Mumber 363186-30-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,6,3,1,8 and 6 respectively; the second part has 2 digits, 3 and 0 respectively. Calculate Digit Verification of CAS Registry Number 363186-30: (8*3)+(7*6)+(6*3)+(5*1)+(4*8)+(3*6)+(2*3)+(1*0)=145 145 % 10 = 5 So 363186-30-5 is a valid CAS Registry Number.