The CAS Registry Mumber 11056-14-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,1,0,5 and 6 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 11056-14: (7*1)+(6*1)+(5*0)+(4*5)+(3*6)+(2*1)+(1*4)=57 57 % 10 = 7 So 11056-14-7 is a valid CAS Registry Number.