The CAS Registry Mumber 11061-73-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,1,0,6 and 1 respectively; the second part has 2 digits, 7 and 3 respectively. Calculate Digit Verification of CAS Registry Number 11061-73: (7*1)+(6*1)+(5*0)+(4*6)+(3*1)+(2*7)+(1*3)=57 57 % 10 = 7 So 11061-73-7 is a valid CAS Registry Number.