The CAS Registry Mumber 19885-52-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,9,8,8 and 5 respectively; the second part has 2 digits, 5 and 2 respectively. Calculate Digit Verification of CAS Registry Number 19885-52: (7*1)+(6*9)+(5*8)+(4*8)+(3*5)+(2*5)+(1*2)=160 160 % 10 = 0 So 19885-52-0 is a valid CAS Registry Number.