The CAS Registry Mumber 117452-45-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,7,4,5 and 2 respectively; the second part has 2 digits, 4 and 5 respectively. Calculate Digit Verification of CAS Registry Number 117452-45: (8*1)+(7*1)+(6*7)+(5*4)+(4*5)+(3*2)+(2*4)+(1*5)=116 116 % 10 = 6 So 117452-45-6 is a valid CAS Registry Number.