The CAS Registry Mumber 94247-13-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,4,2,4 and 7 respectively; the second part has 2 digits, 1 and 3 respectively. Calculate Digit Verification of CAS Registry Number 94247-13: (7*9)+(6*4)+(5*2)+(4*4)+(3*7)+(2*1)+(1*3)=139 139 % 10 = 9 So 94247-13-9 is a valid CAS Registry Number.