The CAS Registry Mumber 360-17-8 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 3,6 and 0 respectively; the second part has 2 digits, 1 and 7 respectively. Calculate Digit Verification of CAS Registry Number 360-17: (5*3)+(4*6)+(3*0)+(2*1)+(1*7)=48 48 % 10 = 8 So 360-17-8 is a valid CAS Registry Number.