The CAS Registry Mumber 117710-14-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,7,7,1 and 0 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 117710-14: (8*1)+(7*1)+(6*7)+(5*7)+(4*1)+(3*0)+(2*1)+(1*4)=102 102 % 10 = 2 So 117710-14-2 is a valid CAS Registry Number.