The CAS Registry Mumber 852635-75-7 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 8,5,2,6,3 and 5 respectively; the second part has 2 digits, 7 and 5 respectively. Calculate Digit Verification of CAS Registry Number 852635-75: (8*8)+(7*5)+(6*2)+(5*6)+(4*3)+(3*5)+(2*7)+(1*5)=187 187 % 10 = 7 So 852635-75-7 is a valid CAS Registry Number.