The CAS Registry Mumber 12773-89-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,2,7,7 and 3 respectively; the second part has 2 digits, 8 and 9 respectively. Calculate Digit Verification of CAS Registry Number 12773-89: (7*1)+(6*2)+(5*7)+(4*7)+(3*3)+(2*8)+(1*9)=116 116 % 10 = 6 So 12773-89-6 is a valid CAS Registry Number.