The CAS Registry Mumber 71162-47-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,1,1,6 and 2 respectively; the second part has 2 digits, 4 and 7 respectively. Calculate Digit Verification of CAS Registry Number 71162-47: (7*7)+(6*1)+(5*1)+(4*6)+(3*2)+(2*4)+(1*7)=105 105 % 10 = 5 So 71162-47-5 is a valid CAS Registry Number.