The CAS Registry Mumber 131544-14-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,1,5,4 and 4 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 131544-14: (8*1)+(7*3)+(6*1)+(5*5)+(4*4)+(3*4)+(2*1)+(1*4)=94 94 % 10 = 4 So 131544-14-4 is a valid CAS Registry Number.