The CAS Registry Mumber 103627-70-9 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,0,3,6,2 and 7 respectively; the second part has 2 digits, 7 and 0 respectively. Calculate Digit Verification of CAS Registry Number 103627-70: (8*1)+(7*0)+(6*3)+(5*6)+(4*2)+(3*7)+(2*7)+(1*0)=99 99 % 10 = 9 So 103627-70-9 is a valid CAS Registry Number.