The CAS Registry Mumber 67322-78-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,7,3,2 and 2 respectively; the second part has 2 digits, 7 and 8 respectively. Calculate Digit Verification of CAS Registry Number 67322-78: (7*6)+(6*7)+(5*3)+(4*2)+(3*2)+(2*7)+(1*8)=135 135 % 10 = 5 So 67322-78-5 is a valid CAS Registry Number.