The CAS Registry Mumber 1440939-88-7 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,4,4,0,9,3 and 9 respectively; the second part has 2 digits, 8 and 8 respectively. Calculate Digit Verification of CAS Registry Number 1440939-88: (9*1)+(8*4)+(7*4)+(6*0)+(5*9)+(4*3)+(3*9)+(2*8)+(1*8)=177 177 % 10 = 7 So 1440939-88-7 is a valid CAS Registry Number.