The CAS Registry Mumber 62020-07-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,2,0,2 and 0 respectively; the second part has 2 digits, 0 and 7 respectively. Calculate Digit Verification of CAS Registry Number 62020-07: (7*6)+(6*2)+(5*0)+(4*2)+(3*0)+(2*0)+(1*7)=69 69 % 10 = 9 So 62020-07-9 is a valid CAS Registry Number.