The CAS Registry Mumber 183114-70-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,8,3,1,1 and 4 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 183114-70: (8*1)+(7*8)+(6*3)+(5*1)+(4*1)+(3*4)+(2*7)+(1*0)=117 117 % 10 = 7 So 183114-70-7 is a valid CAS Registry Number.