The CAS Registry Mumber 73765-01-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,3,7,6 and 5 respectively; the second part has 2 digits, 0 and 1 respectively. Calculate Digit Verification of CAS Registry Number 73765-01: (7*7)+(6*3)+(5*7)+(4*6)+(3*5)+(2*0)+(1*1)=142 142 % 10 = 2 So 73765-01-2 is a valid CAS Registry Number.