The CAS Registry Mumber 79053-50-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,9,0,5 and 3 respectively; the second part has 2 digits, 5 and 0 respectively. Calculate Digit Verification of CAS Registry Number 79053-50: (7*7)+(6*9)+(5*0)+(4*5)+(3*3)+(2*5)+(1*0)=142 142 % 10 = 2 So 79053-50-2 is a valid CAS Registry Number.