The CAS Registry Mumber 75088-44-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,5,0,8 and 8 respectively; the second part has 2 digits, 4 and 4 respectively. Calculate Digit Verification of CAS Registry Number 75088-44: (7*7)+(6*5)+(5*0)+(4*8)+(3*8)+(2*4)+(1*4)=147 147 % 10 = 7 So 75088-44-7 is a valid CAS Registry Number.