The CAS Registry Mumber 82760-88-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,2,7,6 and 0 respectively; the second part has 2 digits, 8 and 8 respectively. Calculate Digit Verification of CAS Registry Number 82760-88: (7*8)+(6*2)+(5*7)+(4*6)+(3*0)+(2*8)+(1*8)=151 151 % 10 = 1 So 82760-88-1 is a valid CAS Registry Number.