The CAS Registry Mumber 77132-94-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,7,1,3 and 2 respectively; the second part has 2 digits, 9 and 4 respectively. Calculate Digit Verification of CAS Registry Number 77132-94: (7*7)+(6*7)+(5*1)+(4*3)+(3*2)+(2*9)+(1*4)=136 136 % 10 = 6 So 77132-94-6 is a valid CAS Registry Number.