The CAS Registry Mumber 92771-58-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,2,7,7 and 1 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 92771-58: (7*9)+(6*2)+(5*7)+(4*7)+(3*1)+(2*5)+(1*8)=159 159 % 10 = 9 So 92771-58-9 is a valid CAS Registry Number.