The CAS Registry Mumber 40519-93-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 4,0,5,1 and 9 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 40519-93: (7*4)+(6*0)+(5*5)+(4*1)+(3*9)+(2*9)+(1*3)=105 105 % 10 = 5 So 40519-93-5 is a valid CAS Registry Number.