The CAS Registry Mumber 131832-04-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,1,8,3 and 2 respectively; the second part has 2 digits, 0 and 4 respectively. Calculate Digit Verification of CAS Registry Number 131832-04: (8*1)+(7*3)+(6*1)+(5*8)+(4*3)+(3*2)+(2*0)+(1*4)=97 97 % 10 = 7 So 131832-04-7 is a valid CAS Registry Number.