The CAS Registry Mumber 194034-61-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,9,4,0,3 and 4 respectively; the second part has 2 digits, 6 and 1 respectively. Calculate Digit Verification of CAS Registry Number 194034-61: (8*1)+(7*9)+(6*4)+(5*0)+(4*3)+(3*4)+(2*6)+(1*1)=132 132 % 10 = 2 So 194034-61-2 is a valid CAS Registry Number.