The CAS Registry Mumber 174512-63-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,7,4,5,1 and 2 respectively; the second part has 2 digits, 6 and 3 respectively. Calculate Digit Verification of CAS Registry Number 174512-63: (8*1)+(7*7)+(6*4)+(5*5)+(4*1)+(3*2)+(2*6)+(1*3)=131 131 % 10 = 1 So 174512-63-1 is a valid CAS Registry Number.