642978-91-4 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 642978-91-4 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 6,4,2,9,7 and 8 respectively; the second part has 2 digits, 9 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 642978-91:
(8*6)+(7*4)+(6*2)+(5*9)+(4*7)+(3*8)+(2*9)+(1*1)=204
204 % 10 = 4
So 642978-91-4 is a valid CAS Registry Number.