The CAS Registry Mumber 1019613-18-3 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,0,1,9,6,1 and 3 respectively; the second part has 2 digits, 1 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1019613-18: (9*1)+(8*0)+(7*1)+(6*9)+(5*6)+(4*1)+(3*3)+(2*1)+(1*8)=123 123 % 10 = 3 So 1019613-18-3 is a valid CAS Registry Number.