The CAS Registry Mumber 5761-36-4 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 5,7,6 and 1 respectively; the second part has 2 digits, 3 and 6 respectively. Calculate Digit Verification of CAS Registry Number 5761-36: (6*5)+(5*7)+(4*6)+(3*1)+(2*3)+(1*6)=104 104 % 10 = 4 So 5761-36-4 is a valid CAS Registry Number.