The CAS Registry Mumber 1245157-39-4 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,2,4,5,1,5 and 7 respectively; the second part has 2 digits, 3 and 9 respectively. Calculate Digit Verification of CAS Registry Number 1245157-39: (9*1)+(8*2)+(7*4)+(6*5)+(5*1)+(4*5)+(3*7)+(2*3)+(1*9)=144 144 % 10 = 4 So 1245157-39-4 is a valid CAS Registry Number.