The CAS Registry Mumber 52776-08-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,2,7,7 and 6 respectively; the second part has 2 digits, 0 and 8 respectively. Calculate Digit Verification of CAS Registry Number 52776-08: (7*5)+(6*2)+(5*7)+(4*7)+(3*6)+(2*0)+(1*8)=136 136 % 10 = 6 So 52776-08-6 is a valid CAS Registry Number.