The CAS Registry Mumber 134202-93-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,4,2,0 and 2 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 134202-93: (8*1)+(7*3)+(6*4)+(5*2)+(4*0)+(3*2)+(2*9)+(1*3)=90 90 % 10 = 0 So 134202-93-0 is a valid CAS Registry Number.