The CAS Registry Mumber 53490-03-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,3,4,9 and 0 respectively; the second part has 2 digits, 0 and 3 respectively. Calculate Digit Verification of CAS Registry Number 53490-03: (7*5)+(6*3)+(5*4)+(4*9)+(3*0)+(2*0)+(1*3)=112 112 % 10 = 2 So 53490-03-2 is a valid CAS Registry Number.