The CAS Registry Mumber 624734-24-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 6,2,4,7,3 and 4 respectively; the second part has 2 digits, 2 and 4 respectively. Calculate Digit Verification of CAS Registry Number 624734-24: (8*6)+(7*2)+(6*4)+(5*7)+(4*3)+(3*4)+(2*2)+(1*4)=153 153 % 10 = 3 So 624734-24-3 is a valid CAS Registry Number.