The CAS Registry Mumber 58351-79-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,8,3,5 and 1 respectively; the second part has 2 digits, 7 and 9 respectively. Calculate Digit Verification of CAS Registry Number 58351-79: (7*5)+(6*8)+(5*3)+(4*5)+(3*1)+(2*7)+(1*9)=144 144 % 10 = 4 So 58351-79-4 is a valid CAS Registry Number.