The CAS Registry Mumber 918824-07-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 9,1,8,8,2 and 4 respectively; the second part has 2 digits, 0 and 7 respectively. Calculate Digit Verification of CAS Registry Number 918824-07: (8*9)+(7*1)+(6*8)+(5*8)+(4*2)+(3*4)+(2*0)+(1*7)=194 194 % 10 = 4 So 918824-07-4 is a valid CAS Registry Number.