The CAS Registry Mumber 164300-60-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,4,3,0 and 0 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 164300-60: (8*1)+(7*6)+(6*4)+(5*3)+(4*0)+(3*0)+(2*6)+(1*0)=101 101 % 10 = 1 So 164300-60-1 is a valid CAS Registry Number.