The CAS Registry Mumber 39002-30-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,9,0,0 and 2 respectively; the second part has 2 digits, 3 and 0 respectively. Calculate Digit Verification of CAS Registry Number 39002-30: (7*3)+(6*9)+(5*0)+(4*0)+(3*2)+(2*3)+(1*0)=87 87 % 10 = 7 So 39002-30-7 is a valid CAS Registry Number.