The CAS Registry Mumber 132351-15-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,3,5 and 1 respectively; the second part has 2 digits, 1 and 5 respectively. Calculate Digit Verification of CAS Registry Number 132351-15: (8*1)+(7*3)+(6*2)+(5*3)+(4*5)+(3*1)+(2*1)+(1*5)=86 86 % 10 = 6 So 132351-15-6 is a valid CAS Registry Number.