The CAS Registry Mumber 92803-57-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,2,8,0 and 3 respectively; the second part has 2 digits, 5 and 7 respectively. Calculate Digit Verification of CAS Registry Number 92803-57: (7*9)+(6*2)+(5*8)+(4*0)+(3*3)+(2*5)+(1*7)=141 141 % 10 = 1 So 92803-57-1 is a valid CAS Registry Number.