The CAS Registry Mumber 1266114-58-2 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,2,6,6,1,1 and 4 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1266114-58: (9*1)+(8*2)+(7*6)+(6*6)+(5*1)+(4*1)+(3*4)+(2*5)+(1*8)=142 142 % 10 = 2 So 1266114-58-2 is a valid CAS Registry Number.