The CAS Registry Mumber 245-44-3 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 2,4 and 5 respectively; the second part has 2 digits, 4 and 4 respectively. Calculate Digit Verification of CAS Registry Number 245-44: (5*2)+(4*4)+(3*5)+(2*4)+(1*4)=53 53 % 10 = 3 So 245-44-3 is a valid CAS Registry Number.