The CAS Registry Mumber 92187-33-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,2,1,8 and 7 respectively; the second part has 2 digits, 3 and 3 respectively. Calculate Digit Verification of CAS Registry Number 92187-33: (7*9)+(6*2)+(5*1)+(4*8)+(3*7)+(2*3)+(1*3)=142 142 % 10 = 2 So 92187-33-2 is a valid CAS Registry Number.