The CAS Registry Mumber 147425-91-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,7,4,2 and 5 respectively; the second part has 2 digits, 9 and 1 respectively. Calculate Digit Verification of CAS Registry Number 147425-91: (8*1)+(7*4)+(6*7)+(5*4)+(4*2)+(3*5)+(2*9)+(1*1)=140 140 % 10 = 0 So 147425-91-0 is a valid CAS Registry Number.