The CAS Registry Mumber 112562-20-6 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,2,5,6 and 2 respectively; the second part has 2 digits, 2 and 0 respectively. Calculate Digit Verification of CAS Registry Number 112562-20: (8*1)+(7*1)+(6*2)+(5*5)+(4*6)+(3*2)+(2*2)+(1*0)=86 86 % 10 = 6 So 112562-20-6 is a valid CAS Registry Number.