The CAS Registry Mumber 118527-46-1 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,1,8,5,2 and 7 respectively; the second part has 2 digits, 4 and 6 respectively. Calculate Digit Verification of CAS Registry Number 118527-46: (8*1)+(7*1)+(6*8)+(5*5)+(4*2)+(3*7)+(2*4)+(1*6)=131 131 % 10 = 1 So 118527-46-1 is a valid CAS Registry Number.