The CAS Registry Mumber 1218784-62-3 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,2,1,8,7,8 and 4 respectively; the second part has 2 digits, 6 and 2 respectively. Calculate Digit Verification of CAS Registry Number 1218784-62: (9*1)+(8*2)+(7*1)+(6*8)+(5*7)+(4*8)+(3*4)+(2*6)+(1*2)=173 173 % 10 = 3 So 1218784-62-3 is a valid CAS Registry Number.