The CAS Registry Mumber 76082-64-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,6,0,8 and 2 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 76082-64: (7*7)+(6*6)+(5*0)+(4*8)+(3*2)+(2*6)+(1*4)=139 139 % 10 = 9 So 76082-64-9 is a valid CAS Registry Number.