The CAS Registry Mumber 103769-32-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,3,7,6 and 9 respectively; the second part has 2 digits, 3 and 2 respectively. Calculate Digit Verification of CAS Registry Number 103769-32: (8*1)+(7*0)+(6*3)+(5*7)+(4*6)+(3*9)+(2*3)+(1*2)=120 120 % 10 = 0 So 103769-32-0 is a valid CAS Registry Number.