The CAS Registry Mumber 359630-27-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 3,5,9,6,3 and 0 respectively; the second part has 2 digits, 2 and 7 respectively. Calculate Digit Verification of CAS Registry Number 359630-27: (8*3)+(7*5)+(6*9)+(5*6)+(4*3)+(3*0)+(2*2)+(1*7)=166 166 % 10 = 6 So 359630-27-6 is a valid CAS Registry Number.