The CAS Registry Mumber 169530-52-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,9,5,3 and 0 respectively; the second part has 2 digits, 5 and 2 respectively. Calculate Digit Verification of CAS Registry Number 169530-52: (8*1)+(7*6)+(6*9)+(5*5)+(4*3)+(3*0)+(2*5)+(1*2)=153 153 % 10 = 3 So 169530-52-3 is a valid CAS Registry Number.