The CAS Registry Mumber 127627-34-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,2,7,6,2 and 7 respectively; the second part has 2 digits, 3 and 4 respectively. Calculate Digit Verification of CAS Registry Number 127627-34: (8*1)+(7*2)+(6*7)+(5*6)+(4*2)+(3*7)+(2*3)+(1*4)=133 133 % 10 = 3 So 127627-34-3 is a valid CAS Registry Number.