The CAS Registry Mumber 1000515-00-3 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,0,0,0,5,1 and 5 respectively; the second part has 2 digits, 0 and 0 respectively. Calculate Digit Verification of CAS Registry Number 1000515-00: (9*1)+(8*0)+(7*0)+(6*0)+(5*5)+(4*1)+(3*5)+(2*0)+(1*0)=53 53 % 10 = 3 So 1000515-00-3 is a valid CAS Registry Number.