The CAS Registry Mumber 244057-70-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 2,4,4,0,5 and 7 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 244057-70: (8*2)+(7*4)+(6*4)+(5*0)+(4*5)+(3*7)+(2*7)+(1*0)=123 123 % 10 = 3 So 244057-70-3 is a valid CAS Registry Number.