The CAS Registry Mumber 114055-20-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,4,0,5 and 5 respectively; the second part has 2 digits, 2 and 0 respectively. Calculate Digit Verification of CAS Registry Number 114055-20: (8*1)+(7*1)+(6*4)+(5*0)+(4*5)+(3*5)+(2*2)+(1*0)=78 78 % 10 = 8 So 114055-20-8 is a valid CAS Registry Number.