The CAS Registry Mumber 78352-88-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,8,3,5 and 2 respectively; the second part has 2 digits, 8 and 8 respectively. Calculate Digit Verification of CAS Registry Number 78352-88: (7*7)+(6*8)+(5*3)+(4*5)+(3*2)+(2*8)+(1*8)=162 162 % 10 = 2 So 78352-88-2 is a valid CAS Registry Number.