The CAS Registry Mumber 17068-76-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,7,0,6 and 8 respectively; the second part has 2 digits, 7 and 6 respectively. Calculate Digit Verification of CAS Registry Number 17068-76: (7*1)+(6*7)+(5*0)+(4*6)+(3*8)+(2*7)+(1*6)=117 117 % 10 = 7 So 17068-76-7 is a valid CAS Registry Number.