The CAS Registry Mumber 145013-71-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,5,0,1 and 3 respectively; the second part has 2 digits, 7 and 1 respectively. Calculate Digit Verification of CAS Registry Number 145013-71: (8*1)+(7*4)+(6*5)+(5*0)+(4*1)+(3*3)+(2*7)+(1*1)=94 94 % 10 = 4 So 145013-71-4 is a valid CAS Registry Number.