The CAS Registry Mumber 3000-64-4 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 3,0,0 and 0 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 3000-64: (6*3)+(5*0)+(4*0)+(3*0)+(2*6)+(1*4)=34 34 % 10 = 4 So 3000-64-4 is a valid CAS Registry Number.