The CAS Registry Mumber 78282-40-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,8,2,8 and 2 respectively; the second part has 2 digits, 4 and 0 respectively. Calculate Digit Verification of CAS Registry Number 78282-40: (7*7)+(6*8)+(5*2)+(4*8)+(3*2)+(2*4)+(1*0)=153 153 % 10 = 3 So 78282-40-3 is a valid CAS Registry Number.