The CAS Registry Mumber 64360-33-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,4,3,6 and 0 respectively; the second part has 2 digits, 3 and 3 respectively. Calculate Digit Verification of CAS Registry Number 64360-33: (7*6)+(6*4)+(5*3)+(4*6)+(3*0)+(2*3)+(1*3)=114 114 % 10 = 4 So 64360-33-4 is a valid CAS Registry Number.