The CAS Registry Mumber 819060-13-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 8,1,9,0,6 and 0 respectively; the second part has 2 digits, 1 and 3 respectively. Calculate Digit Verification of CAS Registry Number 819060-13: (8*8)+(7*1)+(6*9)+(5*0)+(4*6)+(3*0)+(2*1)+(1*3)=154 154 % 10 = 4 So 819060-13-4 is a valid CAS Registry Number.