The CAS Registry Mumber 117052-17-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,7,0,5 and 2 respectively; the second part has 2 digits, 1 and 7 respectively. Calculate Digit Verification of CAS Registry Number 117052-17: (8*1)+(7*1)+(6*7)+(5*0)+(4*5)+(3*2)+(2*1)+(1*7)=92 92 % 10 = 2 So 117052-17-2 is a valid CAS Registry Number.