The CAS Registry Mumber 36390-05-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 3,6,3,9 and 0 respectively; the second part has 2 digits, 0 and 5 respectively. Calculate Digit Verification of CAS Registry Number 36390-05: (7*3)+(6*6)+(5*3)+(4*9)+(3*0)+(2*0)+(1*5)=113 113 % 10 = 3 So 36390-05-3 is a valid CAS Registry Number.