The CAS Registry Mumber 190127-06-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,9,0,1,2 and 7 respectively; the second part has 2 digits, 0 and 6 respectively. Calculate Digit Verification of CAS Registry Number 190127-06: (8*1)+(7*9)+(6*0)+(5*1)+(4*2)+(3*7)+(2*0)+(1*6)=111 111 % 10 = 1 So 190127-06-1 is a valid CAS Registry Number.