The CAS Registry Mumber 180895-71-0 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,8,0,8,9 and 5 respectively; the second part has 2 digits, 7 and 1 respectively. Calculate Digit Verification of CAS Registry Number 180895-71: (8*1)+(7*8)+(6*0)+(5*8)+(4*9)+(3*5)+(2*7)+(1*1)=170 170 % 10 = 0 So 180895-71-0 is a valid CAS Registry Number.