The CAS Registry Mumber 1314039-97-8 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,3,1,4,0,3 and 9 respectively; the second part has 2 digits, 9 and 7 respectively. Calculate Digit Verification of CAS Registry Number 1314039-97: (9*1)+(8*3)+(7*1)+(6*4)+(5*0)+(4*3)+(3*9)+(2*9)+(1*7)=128 128 % 10 = 8 So 1314039-97-8 is a valid CAS Registry Number.