The CAS Registry Mumber 65019-70-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,5,0,1 and 9 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 65019-70: (7*6)+(6*5)+(5*0)+(4*1)+(3*9)+(2*7)+(1*0)=117 117 % 10 = 7 So 65019-70-7 is a valid CAS Registry Number.