The CAS Registry Mumber 106054-52-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,6,0,5 and 4 respectively; the second part has 2 digits, 5 and 2 respectively. Calculate Digit Verification of CAS Registry Number 106054-52: (8*1)+(7*0)+(6*6)+(5*0)+(4*5)+(3*4)+(2*5)+(1*2)=88 88 % 10 = 8 So 106054-52-8 is a valid CAS Registry Number.