The CAS Registry Mumber 102045-70-5 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,2,0,4 and 5 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 102045-70: (8*1)+(7*0)+(6*2)+(5*0)+(4*4)+(3*5)+(2*7)+(1*0)=65 65 % 10 = 5 So 102045-70-5 is a valid CAS Registry Number.