The CAS Registry Mumber 72510-49-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,2,5,1 and 0 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 72510-49: (7*7)+(6*2)+(5*5)+(4*1)+(3*0)+(2*4)+(1*9)=107 107 % 10 = 7 So 72510-49-7 is a valid CAS Registry Number.