The CAS Registry Mumber 6858-46-4 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 6,8,5 and 8 respectively; the second part has 2 digits, 4 and 6 respectively. Calculate Digit Verification of CAS Registry Number 6858-46: (6*6)+(5*8)+(4*5)+(3*8)+(2*4)+(1*6)=134 134 % 10 = 4 So 6858-46-4 is a valid CAS Registry Number.