The CAS Registry Mumber 78932-30-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,8,9,3 and 2 respectively; the second part has 2 digits, 3 and 0 respectively. Calculate Digit Verification of CAS Registry Number 78932-30: (7*7)+(6*8)+(5*9)+(4*3)+(3*2)+(2*3)+(1*0)=166 166 % 10 = 6 So 78932-30-6 is a valid CAS Registry Number.