The CAS Registry Mumber 132948-42-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,2,9,4 and 8 respectively; the second part has 2 digits, 4 and 2 respectively. Calculate Digit Verification of CAS Registry Number 132948-42: (8*1)+(7*3)+(6*2)+(5*9)+(4*4)+(3*8)+(2*4)+(1*2)=136 136 % 10 = 6 So 132948-42-6 is a valid CAS Registry Number.