The CAS Registry Mumber 92712-51-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,2,7,1 and 2 respectively; the second part has 2 digits, 5 and 1 respectively. Calculate Digit Verification of CAS Registry Number 92712-51: (7*9)+(6*2)+(5*7)+(4*1)+(3*2)+(2*5)+(1*1)=131 131 % 10 = 1 So 92712-51-1 is a valid CAS Registry Number.