The CAS Registry Mumber 52003-74-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,2,0,0 and 3 respectively; the second part has 2 digits, 7 and 4 respectively. Calculate Digit Verification of CAS Registry Number 52003-74: (7*5)+(6*2)+(5*0)+(4*0)+(3*3)+(2*7)+(1*4)=74 74 % 10 = 4 So 52003-74-4 is a valid CAS Registry Number.