The CAS Registry Mumber 148148-02-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,4,8,1,4 and 8 respectively; the second part has 2 digits, 0 and 2 respectively. Calculate Digit Verification of CAS Registry Number 148148-02: (8*1)+(7*4)+(6*8)+(5*1)+(4*4)+(3*8)+(2*0)+(1*2)=131 131 % 10 = 1 So 148148-02-1 is a valid CAS Registry Number.