The CAS Registry Mumber 76782-14-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,6,7,8 and 2 respectively; the second part has 2 digits, 1 and 4 respectively. Calculate Digit Verification of CAS Registry Number 76782-14: (7*7)+(6*6)+(5*7)+(4*8)+(3*2)+(2*1)+(1*4)=164 164 % 10 = 4 So 76782-14-4 is a valid CAS Registry Number.