The CAS Registry Mumber 88057-93-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,8,0,5 and 7 respectively; the second part has 2 digits, 9 and 3 respectively. Calculate Digit Verification of CAS Registry Number 88057-93: (7*8)+(6*8)+(5*0)+(4*5)+(3*7)+(2*9)+(1*3)=166 166 % 10 = 6 So 88057-93-6 is a valid CAS Registry Number.