The CAS Registry Mumber 160057-45-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,0,0,5 and 7 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 160057-45: (8*1)+(7*6)+(6*0)+(5*0)+(4*5)+(3*7)+(2*4)+(1*5)=104 104 % 10 = 4 So 160057-45-4 is a valid CAS Registry Number.