The CAS Registry Mumber 1053711-72-0 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,0,5,3,7,1 and 1 respectively; the second part has 2 digits, 7 and 2 respectively. Calculate Digit Verification of CAS Registry Number 1053711-72: (9*1)+(8*0)+(7*5)+(6*3)+(5*7)+(4*1)+(3*1)+(2*7)+(1*2)=120 120 % 10 = 0 So 1053711-72-0 is a valid CAS Registry Number.