The CAS Registry Mumber 54690-63-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,4,6,9 and 0 respectively; the second part has 2 digits, 6 and 3 respectively. Calculate Digit Verification of CAS Registry Number 54690-63: (7*5)+(6*4)+(5*6)+(4*9)+(3*0)+(2*6)+(1*3)=140 140 % 10 = 0 So 54690-63-0 is a valid CAS Registry Number.