The CAS Registry Mumber 78324-12-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,8,3,2 and 4 respectively; the second part has 2 digits, 1 and 2 respectively. Calculate Digit Verification of CAS Registry Number 78324-12: (7*7)+(6*8)+(5*3)+(4*2)+(3*4)+(2*1)+(1*2)=136 136 % 10 = 6 So 78324-12-6 is a valid CAS Registry Number.