The CAS Registry Mumber 17082-87-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,7,0,8 and 2 respectively; the second part has 2 digits, 8 and 7 respectively. Calculate Digit Verification of CAS Registry Number 17082-87: (7*1)+(6*7)+(5*0)+(4*8)+(3*2)+(2*8)+(1*7)=110 110 % 10 = 0 So 17082-87-0 is a valid CAS Registry Number.