The CAS Registry Mumber 78233-10-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,8,2,3 and 3 respectively; the second part has 2 digits, 1 and 0 respectively. Calculate Digit Verification of CAS Registry Number 78233-10: (7*7)+(6*8)+(5*2)+(4*3)+(3*3)+(2*1)+(1*0)=130 130 % 10 = 0 So 78233-10-0 is a valid CAS Registry Number.