The CAS Registry Mumber 130697-58-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,3,0,6,9 and 7 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 130697-58: (8*1)+(7*3)+(6*0)+(5*6)+(4*9)+(3*7)+(2*5)+(1*8)=134 134 % 10 = 4 So 130697-58-4 is a valid CAS Registry Number.