The CAS Registry Mumber 76513-59-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,6,5,1 and 3 respectively; the second part has 2 digits, 5 and 9 respectively. Calculate Digit Verification of CAS Registry Number 76513-59: (7*7)+(6*6)+(5*5)+(4*1)+(3*3)+(2*5)+(1*9)=142 142 % 10 = 2 So 76513-59-2 is a valid CAS Registry Number.