The CAS Registry Mumber 73732-01-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,3,7,3 and 2 respectively; the second part has 2 digits, 0 and 1 respectively. Calculate Digit Verification of CAS Registry Number 73732-01: (7*7)+(6*3)+(5*7)+(4*3)+(3*2)+(2*0)+(1*1)=121 121 % 10 = 1 So 73732-01-1 is a valid CAS Registry Number.