The CAS Registry Mumber 77052-79-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,7,0,5 and 2 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 77052-79: (7*7)+(6*7)+(5*0)+(4*5)+(3*2)+(2*7)+(1*9)=140 140 % 10 = 0 So 77052-79-0 is a valid CAS Registry Number.