The CAS Registry Mumber 112723-64-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,2,7,2 and 3 respectively; the second part has 2 digits, 6 and 4 respectively. Calculate Digit Verification of CAS Registry Number 112723-64: (8*1)+(7*1)+(6*2)+(5*7)+(4*2)+(3*3)+(2*6)+(1*4)=95 95 % 10 = 5 So 112723-64-5 is a valid CAS Registry Number.