The CAS Registry Mumber 805-60-7 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 8,0 and 5 respectively; the second part has 2 digits, 6 and 0 respectively. Calculate Digit Verification of CAS Registry Number 805-60: (5*8)+(4*0)+(3*5)+(2*6)+(1*0)=67 67 % 10 = 7 So 805-60-7 is a valid CAS Registry Number.