The CAS Registry Mumber 70750-58-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,0,7,5 and 0 respectively; the second part has 2 digits, 5 and 8 respectively. Calculate Digit Verification of CAS Registry Number 70750-58: (7*7)+(6*0)+(5*7)+(4*5)+(3*0)+(2*5)+(1*8)=122 122 % 10 = 2 So 70750-58-2 is a valid CAS Registry Number.