The CAS Registry Mumber 70436-63-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,0,4,3 and 6 respectively; the second part has 2 digits, 6 and 3 respectively. Calculate Digit Verification of CAS Registry Number 70436-63: (7*7)+(6*0)+(5*4)+(4*3)+(3*6)+(2*6)+(1*3)=114 114 % 10 = 4 So 70436-63-4 is a valid CAS Registry Number.