The CAS Registry Mumber 57365-15-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,7,3,6 and 5 respectively; the second part has 2 digits, 1 and 5 respectively. Calculate Digit Verification of CAS Registry Number 57365-15: (7*5)+(6*7)+(5*3)+(4*6)+(3*5)+(2*1)+(1*5)=138 138 % 10 = 8 So 57365-15-8 is a valid CAS Registry Number.