The CAS Registry Mumber 61057-44-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 6,1,0,5 and 7 respectively; the second part has 2 digits, 4 and 4 respectively. Calculate Digit Verification of CAS Registry Number 61057-44: (7*6)+(6*1)+(5*0)+(4*5)+(3*7)+(2*4)+(1*4)=101 101 % 10 = 1 So 61057-44-1 is a valid CAS Registry Number.