The CAS Registry Mumber 132948-40-4 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 0 respectively. Calculate Digit Verification of CAS Registry Number 132948-40: (8*1)+(7*3)+(6*2)+(5*9)+(4*4)+(3*8)+(2*4)+(1*0)=134 134 % 10 = 4 So 132948-40-4 is a valid CAS Registry Number.