The CAS Registry Mumber 934237-70-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 9,3,4,2,3 and 7 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 934237-70: (8*9)+(7*3)+(6*4)+(5*2)+(4*3)+(3*7)+(2*7)+(1*0)=174 174 % 10 = 4 So 934237-70-4 is a valid CAS Registry Number.